Pyrimidine compounds

ABSTRACT

The present invention relates to substituted pyrimidines of formula I, their preparation, pharmaceutical compositions containing them and their use as inhibitors of cyclin-dependent kinases (CDKs) and hence their use in the treatment of proliferative disorders and/or viral disorders.

RELATED APPLICATIONS

This application is a continuation of PCT/GB2003/004973, filed on Nov.14, 2003, which claims priority to GB 0226583, filed on Nov. 14, 2002.The entire contents of each of these applications is incorporated hereinby reference in their entirety.

BACKGROUND

We have previously disclosed 2-substituted-4-heteroaryl-pyrimidines andtheir use in the treatment of proliferative disorders (Fischer P M, WangS. PCT Intl. Patent Appl. Publ. WO 01/072745; Cyclacel Limited, UK,2001). These compounds inhibit cyclin-dependent protein kinases (CDKs),in particular CDK4/cyclin D, CDK2/cyclin E, CDK2/cyclin A, andCDK1/cyclin B, i.e. enzyme complexes that are important in human cellcycle progression. Furthermore, 2-phenylamino-4-heteroaryl-pyrimidinespossess selective in vitro and in vivo antiproliferative activityagainst a range of human tumour cells (Wang S, Blake D, Clarke R, DuffS, McClue SJ, McInnes C, Melville J, Stewart K, Taylor P, Westwood R,Wood G, Wu S-Y, Zhelev NZ, Zheleva DI, Walkinshaw M, Lane DP, Fischer PM. Proc. Amer. Assoc. Cancer Res. 2002; 43: 4202).

The present invention seeks to provide further2-substituted-4-heteroaryl-pyrimidines. More specifically, the presentinvention preferably seeks to provide2-substituted-4-heteroaryl-pyrimidines which display improved aqueoussolubility and/or bioavailability.

STATEMENT OF INVENTION

The present invention relates to new2-substituted-4-heteroaryl-pyrimidine derivatives and their use intherapy. More specifically, the invention relates to2-substituted-4-heteroaryl-pyrimidine derivatives having improvedsolubility properties.

A first aspect of the invention relates to a compound of formula I, or apharmaceutically acceptable salt thereof,

wherein:

-   (A) one of X¹ and X² is S, and the other of X¹ and X² is N;    -   “a” is a single bond;    -   “b”, “C”, “d”, “e” and “f” are single or double bonds so as to        form a thiazolyl ring;    -   R² is independently as defined below for R¹, R³⁻⁸; or-   (B) one of X¹ and X² is S, and the other of X¹ and X² is NR¹⁷;    -   “a” and “d” are each double bonds;    -   “b”, “c”, “e” and “f” are each single bonds;    -   R² is oxo; and    -   R¹⁷ is H or alkyl;        where:-   Z is NH, NHCO, NHSO₂, NHCH₂, CH₂, CH₂CH₂, CH═CH, SO₂, or SO;-   R¹, R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are each independently H, alkyl,    alkyl-R⁹, aryl, aryl-R⁹, aralkyl, aralkyl-R⁹, halogeno, NO₂, CN, OH,    O-alkyl, COR⁹, COOR⁹, O-aryl, O—R⁹, NH₂, NH-alkyl, NH-aryl,    N-(alkyl)₂, N-(aryl)₂, N-(alkyl)(aryl), NH—R⁹, N—(R⁹)(R¹⁰),    N-(alkyl)(R⁹), N-(aryl)(R⁹), COOH, CONH₂, CONH-alkyl, CONH-aryl,    CON-(alkyl)(R⁹), CON(aryl)(R⁹), CONH—R⁹, CON—(R⁹)(R¹⁰), SO₃H,    SO₂-alkyl, SO₂-alkyl-R⁹, SO₂-aryl, SO₂-aryl-R⁹, SO₂NH₂, SO₂NH—R⁹,    SO₂N—(R⁹)(R¹⁰), CF₃, CO-alkyl, CO-alkyl-R⁹, CO-aryl, CO-aryl-R⁹ or    R¹¹, wherein alkyl, aryl, aralkyl groups may be further substituted    with one or more groups selected from halogeno, NO₂, OH, O-methyl,    NH₂, COOH, CONH₂ and CF₃;    wherein at least one of R¹, R², R³; R⁴; R⁵; R⁶, R⁷ and R⁸ is an R⁹    or R¹⁰-containing group, or is R¹¹;-   R⁹ and R¹⁰ are each independently solubilising groups selected from:-   (i)    -   a mono-, di- or polyhydroxylated alicyclic group;    -   a di- or polyhydroxylated aliphatic or aromatic group;    -   a carbohydrate derivative;    -   an O— and/or S-containing heterocyclic group optionally        substituted by one or more hydroxyl groups;    -   an aliphatic or aromatic group containing a carboxamide,        sulfoxide, sulfone, or sulfonamide function; or    -   a halogenated alkylcarbonyl group;-   (ii) COOH, SO₃H, OSO₃H, PO₃H₂, or OPO₃H₂;-   (iii) Y, where Y is selected from an alicyclic, aromatic, or    heterocyclic group comprising one or more of the functions ═N—, —O—,    —NH₂, —NH—, a quarternary amine salt, guanidine, and amidine, where    Y is optionally substituted by one or more substituents selected    from:    -   SO₂-alkyl;    -   alkyl optionally substituted by one or more OH groups;    -   CO-alkyl;    -   aralkyl;    -   COO-alkyl; and    -   an ether group optionally substituted by one or more OH groups;        and where Y is other than pyridinyl;-   (iv) a natural or unnatural amino acid, a peptide or a peptide    derivative;-   each R¹¹ is a solubilising group as defined for R⁹ and R¹⁰ in (i)    or (iv) above; or is selected from:-   (v) OSO₃H, PO₃H₂, or OPO₃H₂;-   (vi) Y as defined above, but exluding guanidine and quarternary    amine salts;-   (vii) NHCO(CH₂)_(m)[NHCO(CH₂)_(m′)]_(p)[NHCO(CH₂)_(m″))_(q)Y or    NHCO(CH₂)_(t)NH(CH₂)_(t′)Y where p and q are each 0 or 1, and m, m′,    m″, t and t′ are each independently an integer from 1 to 10; and-   (viii) (CH₂)_(n)NR¹⁴COR¹², (CH₂)_(n′)NR¹⁵SO₂R¹³, or SO₂R¹⁶, where    R¹², R¹³ and R¹⁶ are each alkyl groups optionally comprising one or    more heteroatoms, and which are optionally substituted by one or    more substituents selected from OH, NH₂, halogen and NO₂, R¹⁴ and    R¹⁵ are each independently H or alkyl, and n and n′ are each    independently 0, 1, 2, or 3;-   (ix) an ether or polyether optionally substituted by one or more    hydroxyl groups or one or more Y groups;-   (x) (CH₂)_(r)NH₂; where r is 0, 1, 2, or 3;-   (xi) (CH₂)_(r′)OH; where r′ is 0, 1, 2, or 3;    with the proviso that the compound is other than:-   2-Chloro-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-acetamide;-   N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-methane    sulfonamide;-   2-Chloro-N-{5-[2-(4-fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2yl}-acetamide;-   {3-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-methanol;-   2-{4-[4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-ethanol;    or-   2-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrinidin-2-ylamino]-phenyl}-ethanol.

A second aspect of the invention relates to a pharmaceutical compositioncomprising a compound of formula I as defined above admixed with apharmaceutically acceptable diluent, excipient or carrier.

A third aspect of the invention relates to the use of a compound offormula I as defined above in the preparation of a medicament fortreating a proliferative disorder.

A fourth aspect of the invention relates to the use of a compound offormula Ia, or a pharmaceutically acceptable salt thereof,

wherein:

-   (A) one of X¹ and X² is S, and the other of X¹ and X² is N;    -   “a” is a single bond;    -   “b”, “c”, “d”, “e” and “f” are single or double bonds so as to        form a thiazolyl ring;    -   R² is independently as defined below for R¹, R³⁻⁸; or-   (B) one of X¹ and X² is S, and the other of X¹ and X² is NR¹⁷;    -   “a” and “d” are each double bonds; and    -   “b”, “c” “e” and “f” are each single bonds;    -   R² is oxo;    -   R¹⁷ is H or alkyl;        where:-   Z is NH, NHCO, NHSO₂, NHCH₂, CH₂, CH₂CH₂, CH═CH, SO₂, or SO;-   R¹, R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are each independently H, alkyl,    alkyl-R⁹, aryl, aryl-R⁹, aralkyl, aralkyl-R⁹, halogeno, NO₂, CN, OH,    O-alkyl, COR⁹, COOR⁹, O-aryl, O—R⁹, NH₂, NH-alkyl, NH-aryl,    N-(alkyl)₂, N-(aryl)₂, N-(alkyl)(aryl), NH—R⁹, N—(R⁹)(R¹⁰),    N-(alkyl)(R⁹), N-(aryl)(R⁹), COOH, CONH₂, CONH-alkyl, CONH-aryl,    CON-(alkyl)(R⁹), CON(aryl)(9), CONH—R⁹, CON—(R⁹)(R¹⁰), SO₃H,    SO₂-alkyl, SO₂-alkyl-R⁹, SO₂-aryl, SO₂-aryl-R⁹, SO₂NH₂, SO₂NH—R⁹,    SO₂N—(R⁹)(R¹⁰), CF₃, CO-alkyl, CO-alkyl-R⁹, CO-aryl, CO-aryl-R⁹ or    R¹¹, wherein alkyl, aryl, aralkyl groups may be further substituted    with one or more groups selected from halogeno, NO₂, OH, O-methyl,    NH₂, COOH, CONH₂ and CF₃;    wherein at least one of R¹, R²; R³, R⁴ R⁵, R⁶, R⁷ and R⁸ is an R⁹ or    R¹⁰-containing group, or is R¹¹;-   R⁹ and R¹⁰ are each independently solubilising groups selected from:-   (i)    -   a mono-, di- or polyhydroxylated alicyclic group;    -   a di- or polyhydroxylated aliphatic or aromatic group;    -   a carbohydrate derivative;    -   an O- and/or S-containing heterocyclic group optionally        substituted by one or more hydroxyl groups;    -   an aliphatic or aromatic group containing a carboxamide,        sulfoxide, sulfone, or sulfonamide function; or    -   a halogenated alkylcarbonyl group;-   (ii) COOH, SO₃H, OSO₃H, PO₃H₂, or OPO₃H₂;-   (iii) Y, where Y is selected from an alicyclic, aromatic, or    heterocyclic group comprising one or more of the functions ═N—, —O—,    —NH₂, —NH—, a quarternary amine salt, guanidine, and amidine, where    Y is optionally substituted by one or more substituents selected    from:    -   SO₂-alkyl;    -   alkyl optionally substituted by one or more OH groups;    -   CO-alkyl;    -   aralkyl;    -   COO-alkyl; and    -   an ether group optionally substituted by one or more OH groups;        and where Y is other than pyridinyl;-   (iv) a natural or unnatural amino acid, a peptide or a peptide    derivative;-   each R¹¹ is a solubilising group as defined for R⁹ and R¹⁰ in (i)    or (iv) above; or is selected from:-   (v) OSO₃H, PO₃H₂, or OPO₃H₂;-   (vi) Y as defined above, but exluding guanidine and quarternary    amine salts;-   (vii) NHCO(CH₂)_(m)[NHCO(CH₂)_(m′)]_(p)[NHCO(CH₂)_(m′)]_(q)Y or    NHCO(CH₂)_(t)NH(CH₂)_(t′)Y where p and q are each 0 or 1, and m, m′,    m″, t and t′ are each independently an integer from 1 to 10; and-   (viii) C(CH₂)_(n)NR¹⁴COR¹², (CH₂)_(n′)NR¹⁵SO₂R¹³, or SO₂R¹⁶ where    R¹², R¹³ and R¹⁶ are each alkyl groups optionally comprising one or    more heteroatoms, and which are optionally substituted by one or    more substituents selected from OH, NH₂, halogen and NO₂, R₁₄ and    R¹⁵ are each independently H or alkyl, and n and n′ are each    independently 0, 1, 2, or 3;-   (ix) an ether or polyether optionally substituted by one or more    hydroxyl groups or one or more Y groups;-   (x) (CH₂)_(r)NH₂; where r is 0, 1, 2, or 3;-   (xi) (CH₂)_(r′)OH; where r′ is 0, 1, 2, or 3;    in the preparation of a medicament for treating a viral disorder.

A fifth aspect of the invention relates to the use of a compound offormula I as defined above for inhibiting a protein kinase.

A sixth aspect of the invention relates to the use of a compound offormula I as defined above in an assay for identifying further candidatecompounds capable of inhibiting a cyclin dependent kinase.

DETAILED DESCRIPTION

As used herein the term “alkyl” includes both straight chain andbranched alkyl groups having from 1 to 8 carbon atoms, e.g. methyl,ethyl propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl etc.and the term “lower alkyl” is similarly used for groups having from 1 to4 carbon atoms.

As used herein, the term “aryl” refers to a substituted (mono- or poly-)or unsubstituted monoaromatic or polyaromatic system, wherein saidpolyaromatic system may be fused or unfused. Preferably, the term “aryl”is includes groups having from 6 to 10 carbon atoms, e.g. phenyl,naphthyl etc. The term “aryl” is synonymous with the term “aromatic”.

The term “aralkyl” is used as a conjunction of the terms alkyl and arylas given above.

The term “alicyclic” refers to a cyclic aliphatic group.

The term “aliphatic” takes its normal meaning in the art and includesnon-aromatic groups such as alkanes, alkenes and alkynes and substitutedderivatives thereof.

As used herein, the term “carbohydrate derivative” refers to a compoundof general formula C_(x)(H₂O)_(y) or a derivative thereof. Preferably,the carbohydrate is a a mono-, di- or tri-saccharide. Monosaccharidescan exist as either straight chain or ring-shaped molecules and areclassified according to the number of carbon atoms they possess; trioseshave three carbons, tetroses four, pentoses five and hexoses six. Eachof these subgroups may be further divided into aldoses and ketoses,depending on whether the molecule contains an aldehyde group (—CHO) or aketone group (C═O). Typical examples of monosaccharides include glucose,fructose, and galactose. Disaccharides consist of two linkedmonosaccharide molecules, and include for example, maltose and lactose.Trisaccharides consist of three linked monosaccharide molecules.

The term “derivative” as used herein includes chemical modification ofan entity. Illustrative of such chemical modifications would bereplacement of hydrogen by a halo group, an alkyl group, an acyl groupor an amino group.

The term “heterocycle” refers to a saturated or unsaturated cyclic groupcontaining one or more heteroatoms in the ring.

As used herein the phrase “preparation of a medicament” includes the useof a compound of formula I directly as the medicament in addition to itsuse in a screening programme for further anti-viral agents or in anystage of the manufacture of such a medicament.

In one preferred embodiment, the invention relates to compounds offormula Ib, or pharmaceutically acceptable salts thereof,

-   -   Ib        wherein one of X¹ and X² is S, and the other of X¹ and X² is N,        and Z, R¹⁻⁸ are as defined above.

In another preferred embodiment, the invention relates to compounds offormula Ic, or pharmaceutically acceptable salts thereof,

wherein

-   one of X¹ and X² is S, and the other of X¹ and X² is N;-   Z is NH, NHCO, NHSO₂, NHCH₂, CH₂, CH₂CH₂, CH═CH, SO₂, or SO;-   R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are each independently H, alkyl,    alkyl-R⁹, aryl, aryl-R⁹, aralkyl, aralkyl-R⁹, halogeno, NO₂, CN, OH,    O-alkyl, COR⁹, COOR⁹, O-aryl, O—R⁹, NH₂, NH-alkyl, NH-aryl,    N-(alkyl)₂, N-(aryl)₂, N-(alkyl)(aryl), NH—R⁹, N—(R⁹)(R¹⁰),    N-(alkyl)(R⁹), N-(aryl)(R⁹), COOH, CONH₂, CONH-alkyl, CONH-aryl,    CON-(alkyl)(R⁹), CON(aryl)(R⁹), CONH—R⁹, CON—(R⁹)(R¹⁰), SO₃H,    SO₂-alkyl, SO₂-alkyl-R⁹, SO₂-aryl, SO₂-aryl-R⁹, SO₂NH₂, SO₂NH—R⁹,    SO₂N—(R⁹)(R¹⁰), CF₃, CO-alkyl, CO-alkyl-R⁹, CO-aryl, CO-aryl-R⁹ or    R¹¹, wherein alkyl, aryl, aralkyl groups may be further substituted    with one or more groups selected from halogeno, NO₂, OH, O-methyl,    NH₂, COOH, CONH₂ and CF₃;    wherein at least one of R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ is an R⁹    or R¹⁰-containing group, or is R¹;-   R⁹ and R¹⁰ are each independently solubilising groups selected from:-   (i)    -   a mono-, di- or polyhydroxylated alicyclic group;    -   a di- or polyhydroxylated aliphatic or aromatic group;    -   a carbohydrate derivative;    -   an O- and/or S-containing heterocyclic group optionally        substituted by one or more hydroxyl groups;    -   an aliphatic or aromatic group containing a carboxamide,        sulfoxide, sulfone, or sulfonamide function; or    -   a halogenated alkylcarbonyl group;-   (ii) COOH, SO₃H, OSO₃H, PO₃H₂, or OPO₃H₂;-   (iii) Y, where Y is selected from an alicyclic, aromatic, or    heterocyclic group comprising one or more of the functions ═N—, —O—,    —NH₂, —NH—, a quarternary amine salt, guanidine, and amidine, where    Y is optionally substituted by one or more substituents selected    from:    -   SO₂-alkyl;    -   alkyl optionally substituted by one or more OH groups;    -   CO-alkyl;    -   aralkyl;    -   COO-alkyl; and        -   an ether group optionally substituted by one or more OH            groups; and where Y is other than pyridinyl;-   (iv) a natural or unnatural amino acid, a peptide or a peptide    derivative;-   R¹¹ is a solubilising group as defined for R⁹ and R¹⁰ in (i) or (iv)    above; or is selected from:-   (v) OSO₃H, PO₃H₂, or OPO₃H₂;-   (vi) Y as defined above, but exluding guanidine and quarternary    amine salts;-   (vii) NHCO(CH₂)_(m)[NHCO(CH₂)_(m′)]_(p)[NHCO(CH₂)_(m″)]_(q)Y where p    and q are each 0 or 1, and m, m′ and m″ are each an integer from 1    to 10; and-   (viii) NHCOR¹² or NHSO₂R¹³, where R¹² and R¹³ are each alkyl groups    optionally comprising one or more heteroatoms, and which are    substituted by one or more substituents selected from OH, NH₂,    halogen and NO₂;-   (ix) an ether or polyether optionally substituted by one or more    hydroxyl groups; with the proviso that the compound is other than:-   N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-methanesulfonamide;-   2-Chloro-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-acetamide;    or-   2-Chloro-N-{5-[2-(4-fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide.

Preferably, the compounds of formula I bear a mono- or di-substitutedthiazol-3-yl or thiazol-5-yl radical attached to the pyrimidine ringthrough one of the ring carbon atoms Most preferably, the heterocycle isa thiazol-5-yl group.

Thus, in one preferred embodiment of the invention, X¹ is S and X² is N.

The following preferred features apply to compounds of formula I, Ia, Iband Ic.

In another preferred embodiment, Z is NH.

In another preferred embodiment, R³ is H.

In yet another preferred embodiment, at least one of R², R⁵, R⁶ or R⁷ isan R⁹ or R¹⁰-containing group, or is R¹¹.

In one particularly preferred embodiment, X¹ is S, X² is N, Z is NH, R¹is Me, R² is alkyl or amino, R³ is H, one or two of R⁵, R⁶, and R⁷ areCF₃, OH, O-alkyl, halogeno, NO₂, NH₂, NH-alkyl or N-(alkyl)₂ and atleast one of R², R⁵, R⁶ or R⁷ is an R⁹ or R¹⁰-containing group, or isR¹¹.

In another preferred embodiment, at least one of R¹, R², R³, R⁴, R⁵, R⁶,R⁷ and R⁸ is R¹¹.

In one preferred embodiment, R¹¹ is a solubilising group as defined forR⁹ and R¹⁰ in (i)-(iv) above, or (v)-(x) as defined above.

In another preferred embodiment, R¹¹ is a solubilising group as definedfor R⁹ and R¹⁰ in (i)-(iv) above, or (v)-(vii), (ix)-(x) as definedabove, or is selected from:

-   -   —(CH₂)_(n)NR¹⁴COR¹², where R¹² is an alkyl group optionally        comprising one or more heteroatoms, and which is optionally        substituted by one or more substituents selected from OH, NH₂        and NO₂,    -   —(CH₂), NR¹⁵SO₂R¹³, where R¹³ is an alkyl group optionally        comprising one or more heteroatoms, and which is substituted by        one or more substituents selected from OH, NH₂, halogen and NO₂,    -   SO₂R¹⁶, where R¹⁶ is an alkyl group optionally comprising one or        more heteroatoms, and which is optionally substituted by one or        more substituents selected from OH, NH₂, halogen and NO₂; and    -   R¹⁴ and R¹⁵ are each independently H or alkyl, and n and n′ are        each independently 0, 1, 2, or 3.

Preferably, the solubilising group is R¹¹ and is:

-   (a) Y as defined in above, but exluding guanidine, where Y can also    be an alicyclic, aromatic, or heterocyclic group comprising one or    more ═N— groups;-   (b) NHCO(CH₂)_(m)[NHCO(CH₂)_(m′)]_(p)[NHCO(CH₂)_(m″)]_(q)Y or    NHCO(CH₂)_(t)NH(CH₂)_(t′)Y where p and q are each 0 or 1, and m, m′,    m″, t and t′ are each an integer from 1 to 10; or-   (c) (CH₂)_(n)NR¹⁴COR¹², (CH₂)_(n′)NR¹⁵SO₂R¹³, or SO₂R¹⁶, where R¹²,    R¹³ and R¹⁶ are each alkyl groups optionally comprising one or more    heteroatoms, and which are substituted by one or more substituents    selected from OH, NH₂, halogen and NO₂, R¹⁴ and R¹⁵ are each    independently H or alkyl, and n and n′ are each independently 0, 1,    2, or 3.

Preferably, the solubilising group is R¹¹, and R¹¹ is:

-   (a) Y as defined above, but exluding guanidine, where Y can also be    an alicyclic, aromatic, or heterocyclic group comprising one or more    ═N— groups;-   (b) NHCO(CH₂)_(m)[NHCO(CH₂)_(m′)]_(p)[NHCO(CH₂)_(m″)]_(q)Y where p    and q are each 0 or 1, and m, m′ and m″ are each integers from 1 to    10-   (c) NHCOR¹² or NHSO₂R¹³, where R¹² and R¹³ are each alkyl groups    optionally comprising one or more heteroatoms, and which are    optionally substituted by one or more substituents selected from OH,    NH₂, halogen and NO₂.

Even more preferably, Y is an alicyclic group comprising one or more ofthe functions —O—, NH₂, —NH—, ═N—, a quarternary amine salt, or amidine,and wherein Y is optionally substituted by one or more substituents asdefined above.

More preferably still, Y is a morpholine or piperazine group, each ofwhich may be optionally substituted by one or more substituents selectedfrom SO₂-alkyl, alkyl optionally substituted by one or more OH groups,CO-alkyl, aralkyl, COO-alkyl, and an ether group optionally substitutedby one or more OH groups

In one especially preferred embodiment of the invention, Y is a2-oxo-hexahydro-thien[3,4-d]imidazole group.

In one preferred embodiment, at least one of R², R⁶ or R⁷ is R¹¹.

For this embodiment, preferably R¹¹ is selected from the following:

In one especially preferred embodiment, R⁶ or R⁷ is R¹¹. Morepreferably, R⁶ is R¹¹ and R², R⁴, R⁵, R⁷ and R⁸ are each independentlyselected from alkyl, H, CF₃, OH, O-alkyl, halogeno, NO₂, NH₂, NH-alkyland N-(alkyl)₂. More preferably still, R⁶ is R¹¹ and R², R⁴, R⁵, R⁷ andR⁸ are each independently selected from alkyl, H, O-alkyl, halogeno,NO₂, NH₂ and NH-alkyl. Even more preferably, R⁶ is R¹¹ and R⁴, R⁵, R⁷and R⁸ are all H and R² is selected from alkyl, O-alkyl, NH₂ andNH-alkyl.

Even more preferably still, for this embodiment, R¹¹ is selected from:

In another preferred embodiment, R⁷ is R¹¹ and R⁴, R⁵, R⁶, R⁸ are all H,and R² is selected from alkyl, O-alkyl, NH₂ and NH-alkyl. Preferably,for this embodiment, R¹¹ is selected from:

In another preferred embodiment of the invention, at least one of R² orR⁶ is R¹¹.

For this embodiment, R¹¹ is preferably selected from the following:

In one especially preferred embodiment, R⁶ is R¹¹.

For this embodiment, where R⁶ is R¹¹, preferably R², R⁴, R⁵, R⁷ and R⁸are each independently selected from alkyl, H, CF₃, OH, O-alkyl,halogeno, NO₂, NH₂, NH-alkyl and N-(alkyl)₂.

Even more preferably, R², R⁴, R⁵, R⁷ and R⁸ are each independentlyselected from alkyl, H, O-alkyl, halogeno, NO₂, NH₂ and NH-alkyl.

More preferably still, R⁴, R⁵, R⁷ and R⁸ are all H and R² is selectedfrom alkyl, O-alkyl, NH₂ and NH-alkyl.

More preferably still, R¹¹ is selected from:

In an alternative preferred embodiment, R² is R¹¹.

For this embodiment, R² is R¹¹, preferably R⁴, R⁵, R⁶, R⁷ and R⁸ areeach independently selected from alkyl, H, CF₃, OH, O-alkyl, halogeno,NO₂, NH₂, NH-alkyl and N-(alkyl)-_(2.)

More preferably, R⁴, R⁵, R⁶, R⁷ and R⁸ are each independently selectedfrom H, O-alkyl, halogeno, N-(alkyl)₂, NO₂.

More preferably still, one of R⁵ or R⁷ is selected from NO₂, alkoxy,halogeno and N-(alkyl)₂, and the remainder of R⁴, R⁵, R⁶, R⁷ and R⁸ areall H.

More preferably still, R¹¹ is selected from:

In one preferred embodiment of the invention, R¹ is methyl, Z is NH andR³ is H.

In another embodiment, the compound of the invention is of formula Id,or or a pharmaceutically acceptable salt thereof,

Preferably, R¹ and R³⁻⁸ are as defined above for compounds of formula I,Ia, Ib and Ic. Preferably, R¹⁷ is alkyl, more preferably methyl.

In a preferred embodiment of the invention, the compound of formula I isselected from those listed in Table 1, but excluding compounds [24],[32] and [33].

In one especially preferred embodiment, the compound of formula I isselected from the following:

-   [4-(2-Methoxy-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)amine;-   [4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)amine;-   [4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine;-   [4-(2-N-Methylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholinophenyl)amine;-   [4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine;-   1-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-ethanone;-   [4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-piperazin-1-yl-phenyl)-amine;-   [4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4′-2″-ethoxy]ethanolpiperazino)phenyl]-amine;-   3-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-propan-1-ol;-   2-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-ethanol;-   [4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4-methanesulfonyl-piperazin-1-yl)-phenyl]-amine;-   [4-(4-Benzyl-piperazin-1-yl)-phenyl]-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-amine;-   [4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4-methyl-piperazin-1-yl)-phenyl]-amine;-   [4-(2-Methoxy-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4-methyl-piperazin-1-yl)-phenyl]-amine;-   3-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide;-   (2S)-2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide;-   (2R,3R)-2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide;-   (2R)-2-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide;-   (2S,3S)-2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide;-   4-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide;-   3-Amino-N-{4-methyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide;-   3-Bromo-N-{5-[2-(4-fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamide;-   N-{5-[2-(4-Fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-morpholin-4-yl-propionamide;-   N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-3-morpholin-4-yl-propionamide;-   N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-3-(4-methyl-piperazin-1-yl)-propionamide;-   2-Chloro-N-{5-[2-(3-chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide;-   2-Chloro-N-{5-[2-(3-methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide;-   2-Chloro-N-{5-[2-(4-dimethylamino-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide;-   4-({4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-ylcarbamoyl}-methyl)-piperazine-1-carboxylic    acid tert-butyl ester;-   N-{5-[2-(4-Dimethylamino-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl)-2-[2-(2-hydroxy-ethoxy)-ethylamino]-acetamide;-   6-[5-(2-Oxo-hexahydro-thieno[3,4-d]imidazol-4-yl)-pentanoylamino]-hexanoic    acid    (2-{4-methyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-thiazol-2-ylcarbamoyl}-ethyl)-amide;-   N-{5-[2-(4-Fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-methanesulfonamide;-   3-Bromo-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide;-   3-(1-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperidin-4-yl)-propan-1-ol;-   2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide;    and-   2-Chloro-N-{5-[2-(4-chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide.

In a further preferred embodiment of the invention, said compound offormula I is selected from the following:

-   [4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine;-   [4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine;-   [4-(2-N-methylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholinophenyl)-amine;-   (2R,3R)-2-amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide;-   (2R)-2-amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide;    and-   N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-3-morpholin-4-yl-propionamide.

In one preferred embodiment the compound of formula I is capable ofexibiting an antiproliferative effect in human cell lines, as measuredby a standard 72h MTT cytotoxicity assay. Preferably, the compound offormula I exihibits an IC₅₀ value of less than 10 μM, more preferablyless than 5 μM, even more preferably less than 1 μM as measured by saidMTT assay. More preferably, the compound of formula I is selected fromthe following: [4], [8], [12], [14], [16], [22], [24], [25], [29], [32],[33], [39], [40], [50], [53], [61], [57], [62], [63], [64], [65] and[77]. More preferably still, the compound exihibits an IC₅₀ value ofless than 0.5 less μM, more preferably still less than 0.2 μM. Even morepreferably, the compound is selected from the following: [24], [25],[32], [33], [50], [62] and [64].

In another preferred embodiment, the compound of formula I is selectedfrom [1], [11], [15] and [16].

In another preferred embodiment, the compound of formula I is capable ofinhibiting one or more protein kinases, as measured by the assaysdescribed in the accompanying Examples section. Preferably, the compoundof formula I exihibits an IC₅₀ value of less than 10 μM, more preferablyless than 5 μM, even more preferably less than 1 μM or less than 0.5less μM, more preferably still less than 0.1 μM. More preferably, thecompound of formula I is selected from the following: [11], [13], [14],[15], [20], [21], [22], [24], [25], [32], [50], [53], [54], [55], [56],[57], [59], [61], [62], [64], [68], [71], [82], [83], [84] and [85].More preferably still, the compound exibits an IC₅₀ value of less than0.01 μM. Even more preferably, the compound is selected from thefollowing: [11], [22], [24], [32], [50], [62], [71] and [85].

In yet another preferred embodiment, the compound of formula I isselected from [1], [3], [11], [15] and [16].

The present invention provides a series of compounds equipped withsolubilising functions on the phenyl and/or heteroaryl rings of the2-phenylamino-4-heteroaryl-pyrimidine system. Modification withsolubilising moieties has preserved the desired in vitro biologicalactivity (inhibition of CDKs and cytotoxicity against transformed humancells) and in some cases has led to surprising and unexpected increasesin potency. Furthermore, in vivo absorption, and oral bioavailability inparticular can also be improved using the solubilising strategiespresented herein.

Therapeutic Use

The compounds of formula I have been found to possess anti-proliferativeactivity and are therefore believed to be of use in the treatment ofproliferative disorders such as cancers, leukaemias and other disordersassociated with uncontrolled cellular proliferation such as psoriasisand restenosis. As defined herein, an anti-proliferative effect withinthe scope of the present invention may be demonstrated by the ability toinhibit cell proliferation in an in vitro whole cell assay, for exampleusing any of the cell lines AGS, H1299 or SJSA-1, or by showinginhibition of the interaction between HDM2 and p53 in an appropriateassay. These assays, including methods for their performance, aredescribed in more detail in the accompanying Examples. Using such assaysit may be determined whether a compound is anti-proliferative in thecontext of the present invention.

On preferred embodiment of the present invention therefore relates tothe use of one or more compounds of formula I in the treatment ofproliferative disorders. Preferably, the proliferative disorder is acancer or leukaemia. The term proliferative disorder is used herein in abroad sense to include any disorder that requires control of the cellcycle, for example cardiovascular disorders such as restenosis andcardiomyopathy, auto-immune disorders such as glomerulonephrilis andrheumatoid arthritis, dermatological disorders such as psoriasis,anti-inflammatory, anti-fungal, antiparasitic disorders such as malaria,emphysema and alopecia. In these disorders, the compounds of the presentinvention may induce apoptosis or maintain stasis within the desiredcells as required.

The compounds of the invention may inhibit any of the steps or stages inthe cell cycle, for example, formation of the nuclear envelope, exitfrom the quiescent phase of the cell cycle (G0), G1 progression,chromosome decondensation, nuclear envelope breakdown, START, initiationof DNA replication, progression of DNA replication, termination of DNAreplication, centrosome duplication, G2 progression, activation ofmitotic or meiotic functions, chromosome condensation, centrosomeseparation, microtubule nucleation, spindle formation and function,interactions with microtubule motor proteins, chromatid separation andsegregation, inactivation of mitotic functions, formation of contractilering, and cytokinesis functions. In particular, the compounds of theinvention may influence certain gene functions such as chromatinbinding, formation of replication complexes, replication licensing,phosphorylation or other secondary modification activity, proteolyticdegradation, microtubule binding, actin binding, septin binding,microtubule organising centre nucleation activity and binding tocomponents of cell cycle signalling pathways.

In one embodiment of the invention, the compound of formula I or Ia isadministered in an amount sufficient to inhibit at least one CDK enzyme.

In a more preferred embodiment of the invention, the compound of formulaIa is preferably administered in an amount sufficient to inhibit one ormore of the host cell CDKs involved in viral replication, i.e. CDK2,CDK7, CDK8, and CDK9 [Wang D, De la Fuente C, Deng L, Wang L, ZilbermanI, Eadie C, Healey M, Stein D, Denny T, Harrison LE, Meijer L, KashanchiF. Inhibition of human immunodeficiency virus type 1 transcription bychemical cyclin-dependent kinase inhibitors. J. Virol. 2001; 75:7266-7279].

As defined herein, an anti-viral effect within the scope of the presentinvention may be demonstrated by the ability to inhibit CDK2, CDK7, CDK8or CDK9. Assays for determining CDK activity are described in moredetail in the accompanying examples.

Using such enzymes assays it may be determined whether a compound isanti-viral in the context of the present invention.

In a particularly preferred embodiment, the compounds of formula Ia areuseful in the treatment of viral disorders, such as humancytomegalovirus (HCMV), herpes simplex virus type 1 (HSV-1), humanimmunodeficiency virus type 1 (HIV-1), and varicella zoster virus (VZV).

In a particularly preferred embodiment, the invention relates to the useof one or more compounds of formula Ia in the treatment of a viraldisorder which is CDK dependent or sensitive. CDK dependent disordersare associated with an above normal level of activity of one or more CDKenzymes. Such disorders preferably associated with an abnormal level ofactivity of CDK2, CDK7, CDK8 and/or CDK9. A CDK sensitive disorder is adisorder in which an aberration in the CDK level is not the primarycause, but is downstream of the primary metabolic aberration. In suchscenarios, CDK2, CDK7, CDK8 and/or CDK9 can be said to be part of thesensitive metabolic pathway and CDK inhibitors may therefore be activein treating such disorders.

One preferred embodiment of the invention relates to the use of acompound of formula Ie, or a pharmaceutically acceptable salt thereof,

wherein

-   one of X¹ and X² is S, and the other of X¹ and X² is N;-   Z is NH, NHCO, NHSO₂, NHCH₂, CH₂, CH₂CH₂, CH═CH, SO₂, or SO;-   R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are each independently H, alkyl,    alkyl-R⁹, aryl, aryl-R⁹, aralkyl, aralkyl-R⁹, halogeno, NO₂, CN, OH,    O-alkyl, COR⁹, COOR⁹, O-aryl, O—R⁹, NH₂, NH-alkyl, NH-aryl,    N-(alkyl)₂, N-(aryl)₂, N-(alkyl)(aryl), NH—R⁹, N—(R⁹)(R¹⁰),    N-(alkyl)(R⁹), N-(aryl)(R⁹), COOH, CONH₂, CONH-alkyl, CONH-aryl,    CON-(alkyl)(R⁹), CON(aryl)(R⁹), CONH—R⁹, CON—(R⁹)(R¹⁰), SO₃H,    SO₂-alkyl, SO₂-alkyl-R⁹, SO₂-aryl, SO₂-aryl-R⁹, SO₂NH₂, SO₂NH—R⁹,    SO₂N—(R⁹)(R¹⁰), CF₃, CO-alkyl, CO-alkyl-R⁹, CO-aryl, CO-aryl-R⁹ or    R¹¹, wherein alkyl, aryl, aralkyl groups may be further substituted    with one or more groups selected from halogeno, NO₂, OH, O-methyl,    NH₂, COOH, CONH₂ and CF₃;    wherein at least one of R¹, R², R³, R⁴, R⁵, R⁶, R⁷ and R⁸ is an R⁹    or R¹⁰-containing group, or is R¹¹;-   R⁹ and R¹⁰ are each independently solubilising groups selected from:-   (i)    -   a mono-, di- or polyhydroxylated alicyclic group;    -   a di- or polyhydroxylated aliphatic or aromatic group;    -   a carbohydrate derivative;    -   an O— and/or S-containing heterocyclic group optionally        substituted by one or more hydroxyl groups;    -   an aliphatic or aromatic group containing a carboxamide,        sulfoxide, sulfone, or sulfonamide function; or    -   a halogenated alkylcarbonyl group;-   (ii) COOH, SO₃H, OSO₃H, PO₃H₂, or OPO₃H₂;    -   (iii) Y, where Y is selected from an alicyclic, aromatic, or        heterocyclic group comprising one or more of the functions ═N—,        —O—, —NH₂, —NH—, a quarternary amine salt, guanidine, and        amidine, where Y is optionally substituted by one or more        substituents selected from:    -   SO₂-alkyl;    -   alkyl optionally substituted by one or more OH groups;    -   CO-alkyl;    -   aralkyl;    -   COO-alkyl; and        -   an ether group optionally substituted by one or more OH            groups; and where Y is other than pyridinyl;-   (iv) a natural or unnatural amino acid, a peptide or a peptide    derivative;-   R¹¹ is a solubilising group as defined for R⁹ and R¹⁰ in (i) or (iv)    above; or is selected from:-   (v) OSO₃H, PO₃H₂, or OPO₃H₂;-   (vi) Y as defined above, but exluding guanidine and quarternary    amine salts;-   (vii) NHCO(CH₂)_(m)[NHCO(CH₂)_(m′)]_(p)[NHCO(CH₂)_(m″)]_(q)Y where p    and q are each 0 or 1, and m, m′ and m″ are each an integer from 1    to 10; and-   (viii) NHCOR¹² or NHSO₂R¹³, where R¹² and R¹³ are each alkyl groups    optionally comprising one or more heteroatoms, and which are    substituted by one or more substituents selected from OH, NH₂,    halogen and NO₂;-   (ix) an ether or polyether optionally substituted by one or more    hydroxyl groups; in the preparation of a medicament for treating a    viral disorder.

Preferred features are as defined above for compounds of formula I, Ia,Ib and Ic.

In a preferred embodiment, the compound of formula Ia is selected fromthose listed in Table 1.

More preferably, said compound of formula Ia is selected from thefollowing: [1], [3], [4], [15] and [53].

For use in the treatment of viral disorders, preferably the compound offormula Ia is capable of inhibiting CK2, CDK7 and/or CDK9 and isselected from the following:

-   [4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine;-   2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide;-   2-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide;-   [4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine;-   [4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine;-   3-(1-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperidin-4-yl)-propan-1-ol;-   N-{5-[2-(4-Fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-morpholin-4-yl-propionamide;-   3-Bromo-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide;-   N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-3-morpholin-4-yl-propionamide;-   N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-3-(4-methyl-piperazin-1-yl)-propionamide;-   [4-(2-Methoxy-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4-methyl-piperazin-1-yl)-phenyl]-amine;-   [4-(4-Benzyl-piperazin-1-yl)-phenyl]-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-amine;    and-   3-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide.

The following compound is observed to be a particularly effectiveanti-viral agent, as demonstrated by cell based assays:[4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine.

Another aspect of the invention relates to the use of a compound offormula I or Ia as an anti-mitotic agent.

Yet another aspect of the invention relates to the use of a compound offormula I or Ia for treating a neurodegenerative disorder.

Preferably, the neurodegenerative disorder is neuronal apoptosis.

Another aspect of the invention relates to the use of a compound offormula I or Ia as an antiviral agent.

Thus, another aspect of the invention relates to the use of a compoundof the invention in the preparation of a medicament for treating a viraldisorder, such as human cytomegalovirus (HCMV), herpes simplex virustype 1 (HSV-1), human immunodeficiency virus type 1 (HIV-1), andvaricella zoster virus (VZV).

In a more preferred embodiment of the invention, the compound of theinvention is administered in an amount sufficient to inhibit one or moreof the host cell CDKs involved in viral replication, i.e. CDK2, CDK7,CDK8, and CDK9 [Wang D, De la Fuente C, Deng L, Wang L, Zilberman I,Eadie C, Healey M, Stein D, Denny T, Harrison LE, Meijer L, Kashanchi F.Inhibition of human immunodeficiency virus type 1 transcription bychemical cyclin-dependent kinase inhibitors. J. Virol. 2001; 75:7266-7279].

As defined herein, an anti-viral effect within the scope of the presentinvention may be demonstrated by the ability to inhibit CDK2, CDK7, CDK8or CDK9.

In a particularly preferred embodiment, the invention relates to the useof one or more compounds of the invention in the treatment of a viraldisorder which is CDK dependent or sensitive. CDK dependent disordersare associated with an above normal level of activity of one or more CDKenzymes. Such disorders preferably associated with an abnormal level ofactivity of CDK2, CDK7, CDK8 and/or CDK9. A CDK sensitive disorder is adisorder in which an aberration in the CDK level is not the primarycause, but is downstream of the primary metabolic aberration. In suchscenarios, CDK2, CDK7, CDK8 and/or CDK9 can be said to be part of thesensitive metabolic pathway and CDK inhibitors may therefore be activein treating such disorders.

Another aspect of the invention relates to the use of compounds offormula I or Ia, or pharmaceutically accetable salts thereof, in thepreparation of a medicament for treating diabetes.

In a particularly preferred embodiment, the diabetes is type IIdiabetes.

GSK3 is one of several protein kinases that phosphorylate glycogensynthase (GS). The stimulation of glycogen synthesis by insulin inskeletal muscle results from the dephosphorylation and activation of GS.GSK3's action on GS thus results in the latter's deactivation and thussuppression of the conversion of glucose into glycogen in muscles.

Type II diabetes (non-insulin dependent diabetes mellitus) is amulti-factorial disease. Hyperglycaemia is due to insulin resistance inthe liver, muscles, and other tissues, coupled with impaired secretionof insulin. Skeletal muscle is the main site for insulin-stimulatedglucose uptake, there it is either removed from circulation or convertedto glycogen. Muscle glycogen deposition is the main determinant inglucose homeostasis and type II diabetics have defective muscle glycogenstorage. There is evidence that an increase in GSK3 activity isimportant in type II diabetes [Chen, Y. H.; Hansen, L.; Chen, M. X.;Bjorbaek, C.; Vestergaard, H.; Hansen, T.; Cohen, P. T.; Pedersen, O.Diabetes, 1994, 43, 1234]. Furthermore, it has been demonstrated thatGSK3 is over-expressed in muscle cells of type II diabetics and that aninverse correlation exists between skeletal muscle GSK3 activity andinsulin action [Nikoulina, S. E.; Ciaraldi, T. P.; Mudaliar, S.;Mohideen, P.; Carter, L.; Henry, R. R. Diabetes, 2000, 49, 263].

GSK3 inhibition is therefore of therapeutic significance in thetreatment of diabetes, particularly type II, and diabetic neuropathy.

It is notable that GSK3 is known to phosphorylate many substrates otherthan GS, and is thus involved in the regulation of multiple biochemicalpathways. For example, GSK is highly expressed in the central andperipheral nervous systems.

Another aspect of the invention therefore relates to the use ofcompounds of formula I or Ia, or pharmaceutically acceptable saltsthereof, in the preparation of a medicament for treating a CNSdisorders, for example neurodegenerative disorders.

Preferably, the CNS disorder is Alzheimer's disease.

Tau is a GSK-3 substrate which has been implicated in the etiology ofAlzheimer's disease. In healthy nerve cells, Tau co-assembles withtubulin into microtubules. However, in Alzheimer's disease, tau formslarge tangles of filaments, which disrupt the microtubule structures inthe nerve cell, thereby impairing the transport of nutrients as well asthe transmission of neuronal messages.

Without wishing to be bound by theory, it is believed that GSK3inhibitors may be able to prevent and/or reverse the abnormalhyperphosphorylation of the microtubule-associated protein tau that isan invariant feature of Alzheimer's disease and a number of otherneurodegenerative diseases, such as progressive supranuclear palsy,corticobasal degeneration and Pick's disease. Mutations in the tau genecause inherited forms of fronto-temporal dementia, further underscoringthe relevance of tau protein dysfunction for the neurodegenerativeprocess [Goedert, M. Curr. Opin. Gen. Dev., 2001, 11, 343]. Anotheraspect of the invention relates to the use of compounds of formula I orIa, or pharmaceutically acceptable salts thereof, in the preparation ofa medicament for treating bipolar disorder.

Yet another aspect of the invention relates to the use of compounds offormula I or Ia, or pharmaceutically acceptable salts thereof, in thepreparation of a medicament for treating a stroke.

Reducing neuronal apoptosis is an important therapeutic goal in thecontext of head trauma, stroke, epilepsy, and motor neuron disease[Mattson, M. P. Nat. Rev. Mol. Cell. Biol., 2000, 1, 120]. Therefore,GSK3 as a pro-apoptotic factor in neuronal cells makes this proteinkinase an attractive therapeutic target for the design of inhibitorydrugs to treat these diseases.

Yet another aspect of the invention relates to the use of compounds offormula I or Ia, or pharmaceutically acceptable salts thereof, in thepreparation of a medicament for treating alopecia.

Hair growth is controlled by the Wnt signalling pathway, in particularWnt-3. In tissue-culture model systems of the skin, the expression ofnon-degradable mutants of β-catenin leads to a dramatic increase in thepopulation of putative stem cells, which have greater proliferativepotential [Zhu, A. J.; Watt, F. M. Development, 1999, 126, 2285]. Thispopulation of stem cells expresses a higher level ofnon-cadherin-associated β-catenin [DasGupta, R.; Fuchs, E Development,1999, 126; 45571], which may contribute to their high proliferativepotential. Moreover, transgenic mice overexpressing a truncatedβ-catenin in the skin undergo de novo hair-follicle morphogenesis, whichnormally is only established during embryogenesis. The ectopicapplication of GSK3 inhibitors may therefore be therapeutically usefulin the treatment of baldness and in restoring hair growth followingchemotherapy-induced alopecia.

A further aspect of the invention relates to a method of treating aGSK3-dependent disorder, said method comprising administering to asubject in need thereof, a compound of formula I or Ia, or apharmaceutically acceptable salt thereof, as defined above in an amountsufficient to inhibit GSK3.

Preferably, the compound of the invention, or pharmaceuticallyacceptable salt thereof, is administered in an amount sufficient toinhibit GSK3β.

In one embodiment of the invention, the compound of the invention isadministered in an amount sufficient to inhibit at least one PLK enzyme.

The polo-like kinases (PLKs) constitute a family of serine/threonineprotein kinases. Mitotic Drosophila melanogaster mutants at the pololocus display spindle abnormalities [Sunkel et al., J. Cell Sci., 1988,89, 25] and polo was found to encode a mitotic kinase [Llamazares etal., Genes Dev., 1991, 5, 2153]. In humans, there exist three closelyrelated PLKs [Glover et al., Genes Dev., 1998, 12, 3777]. They contain ahighly homologous amino-terminal catalytic kinase domain and theircarboxyl termini contain two or three conserved regions, the polo boxes.The function of the polo boxes remains incompletely understood but theyare implicated in the targeting of PLKs to subcellular compartments [Leeet al., Proc. Natl. Acad. Sci. USA, 1998, 95, 9301; Leung et al., Nat.Struct. Biol., 2002, 9, 719], mediation of interactions with otherproteins [Kauselmann et al., EMBO J., 1999, 18, 5528], or may constitutepart of an autoregulatory domain [Nigg, Curr. Opin. Cell Biol., 1998,10, 776]. Furthermore, the polo box-dependent PLK1 activity is requiredfor proper metaphase/anaphase transition and cytokinesis [Yuan et al.,Cancer Res., 2002, 62, 4186; Seong et al., J. Biol. Chem., 2002, 277,32282].

Studies have shown that human PLKs regulate some fundamental aspects ofmitosis [Lane et al., J. Cell. Biol., 1996, 135, 1701; Cogswell et al.,Cell Growth Differ., 2000, 11, 615]. In particular, PLK1 activity isbelieved to be necessary for the functional maturation of centrosomes inlate G2/early prophase and subsequent establishment of a bipolarspindle. Depletion of cellular PLK1 through the small interfering RNA(siRNA) technique has also confirmed that this protein is required formultiple mitotic processes and completion of cytokinesis [Liu et al.,Proc. Natl. Acad. Sci. USA, 2002, 99, 8672].

In a more preferred embodiment of the invention, the compound of theinvention is administered in an amount sufficient to inhibit PLK1.

Of the three human PLKs, PLK1 is the best characterized; it regulates anumber of cell division cycle effects, including the onset of mitosis[Toyoshima-Morimoto et al., Nature, 2001, 410, 215; Roshak et al., Cell.Signalling, 2000, 12, 405], DNA-damage checkpoint activation [Smits etal., Nat. Cell Biol., 2000; 2, 672; van Vugt et al., J. Biol. Chem.,2001, 276, 41656], regulation of the anaphase promoting complex [Sumaraet al., Mol. Cell, 2002, 9, 515; Golan et al., J. Biol. Chem., 2002,277, 15552; Kotani et al., Mol. Cell, 1998, 1, 371], phosphorylation ofthe proteasome [Feng et al., Cell Growth Differ., 2001, 12, 29], andcentrosome duplication and maturation [Dai et al., Oncogene, 2002, 21,6195].

Specifically, initiation of mitosis requires activation of M-phasepromoting factor (MPF), the complex between the cyclin dependent kinaseCDK1 and B-type cyclins [Nurse, Nature, 1990, 344, 503]. The latteraccumulate during the S and G2 phases of the cell cycle and promote theinhibitory phosphorylation of the MPF complex by WEE1, MIK1, and MYT1kinases. At the end of the G2 phase, corresponding dephosphorylation bythe dual-specificity phosphatase CDC25C triggers the activation of MPF[Nigg, Nat. Rev. Mol. Cell Biol., 2001, 2, 21]. In interphase, cyclin Blocalizes to the cytoplasm [Hagting et al., EMBO J., 1998, 17, 4127], itthen becomes phosphorylated during prophase and this event causesnuclear translocation [Hagting et al., Curr. Biol., 1999, 9, 680; Yanget al., J. Biol. Chem., 2001, 276, 3604]. The nuclear accumulation ofactive MPF during prophase is thought to be important for initiatingM-phase events [Takizawa et al., Curr. Opin. Cell Biol., 2000, 12, 658].However, nuclear MPF is kept inactive by WEE1 unless counteracted byCDC25C. The phosphatase CDC25C itself, localized to the cytoplasm duringinterphase, accumulates in the nucleus in prophase [Seki et al., Mol.Biol. Cell, 1992, 3, 1373; Heald et al., Cell, 1993, 74, 463; Dalal etal., Mol. Cell. Biol., 1999, 19, 4465]. The nuclear entry of both cyclinB [Toyoshima-Morimoto et al., Nature, 2001, 410, 215] and CDC25C[Toyoshima-Morimoto et al., EMBO Rep., 2002, 3, 341] are promotedthrough phosphorylation by PLK1 [Roshak et al., Cell. Signalling, 2000,12, 405]. This kinase is an important regulator of M-phase initiation.

In one particularly preferred embodiment, the compounds of the inventionare ATP-antagonistic inhibitors of PLK1.

In the present context ATP antagonism refers to the ability of aninhibitor compound to diminish or prevent PLK catalytic activity, i.e.phosphotransfer from ATP to a macromolecular PLK substrate, by virtue ofreversibly or irreversibly binding at the enzyme's active site in such amanner as to impair or abolish ATP binding.

In another preferred embodiment, the compound of the invention isadministered in an amount sufficient to inhibit PLK2 and/or PLK3.

Mammalian PLK2 (also known as SNK) and PLK3 (also known as PRK and FNK)were originally shown to be immediate early gene products. PLK3 kinaseactivity appears to peak during late S and G2 phase. It is alsoactivated during DNA damage checkpoint activation and severe oxidativestress. PLK3 also plays an important role in the regulation ofmicrotubule dynamics and centrosome function in the cell and deregulatedPLK3 expression results in cell cycle arrest and apoptosis [Wang et al.,Mol. Cell. Biol., 2002, 22, 3450]. PLK2 is the least well understoodhomologue of the three PLKs. Both PLK2 and PLK3 may have additionalimportant post-mitotic functions [Kauselmann et al., EMBO J., 1999, 18,5528].

Another aspect of the invention relates to the use of a compound offormula I for inhibiting a protein kinase.

In a preferred embodiment of this aspect, the protein kinase is a cyclindependent kinase. Preferably, the protein kinase is CDK1, CDK2, CDK3,CDK4, CDK6, CDK7, CDK8 or CDK9, more preferably CDK2.

A further aspect of the invention relates to a method of inhibiting aprotein kinase, said method comprising contacting said protein kinasewith a compound of formula I.

In a preferred embodiment of this aspect, the protein kinase is a cyclindependent kinase, even more preferably CDK2.

Pharmaceutical Compositions

A further aspect of the invention relates to a pharmaceuticalcomposition comprising a compound of formula I as defined for said firstaspect admixed with one or more pharmaceutically acceptable diluents,excipients or carriers. Even though the compounds of the presentinvention (including their pharmaceutically acceptable salts, esters andpharmaceutically acceptable solvates) can be administered alone, theywill generally be administered in admixture with a pharmaceuticalcarrier, excipient or diluent, particularly for human therapy. Thepharmaceutical compositions may be for human or animal usage in humanand veterinary medicine.

Examples of such suitable excipients for the various different forms ofpharmaceutical compositions described herein may be found in the“Handbook of Pharmaceutical Excipients, 2^(nd) Edition, (1994), Editedby A Wade and P J Weller.

Acceptable carriers or diluents for therapeutic use are well known inthe pharmaceutical art, and are described, for example, in Remington'sPharmaceutical Sciences, Mack Publishing Co. (A. R. Gennaro edit. 1985).

Examples of suitable carriers include lactose, starch, glucose, methylcellulose, magnesium stearate, mannitol, sorbitol and the like. Examplesof suitable diluents include ethanol, glycerol and water.

The choice of pharmaceutical carrier, excipient or diluent can beselected with regard to the intended route of administration andstandard pharmaceutical practice. The pharmaceutical compositions maycomprise as, or in addition to, the carrier, excipient or diluent anysuitable binder(s), lubricant(s), suspending agent(s), coating agent(s),solubilising agent(s).

Examples of suitable binders include starch, gelatin, natural sugarssuch as glucose, anhydrous lactose, free-flow lactose, beta-lactose,corn sweeteners, natural and synthetic gums, such as acacia, tragacanthor sodium alginate, carboxymethyl cellulose and polyethylene glycol.

Examples of suitable lubricants include sodium oleate, sodium stearate,magnesium stearate, sodium benzoate, sodium acetate, sodium chloride andthe like.

Preservatives, stabilizers, dyes and even flavoring agents may beprovided in the pharmaceutical composition. Examples of preservativesinclude sodium benzoate, sorbic acid and esters of p-hydroxybenzoicacid. Antioxidants and suspending agents may be also used.

Salts/Esters

The compounds of formula I or Ia can be present as salts or esters, inparticular pharmaceutically acceptable salts or esters.

Pharmaceutically acceptable salts of the compounds of the inventioninclude suitable acid addition or base salts thereof. A review ofsuitable pharmaceutical salts may be found in Berge et al, J Pharm Sci,66, 1-19 (1977). Salts are formed, for example with strong inorganicacids such as mineral acids, e.g. sulphuric acid, phosphoric acid orhydrohalic acids; with strong organic carboxylic acids, such asalkanecarboxylic acids of 1 to 4 carbon atoms which are unsubstituted orsubstituted (e.g., by halogen), such as acetic acid; with saturated orunsaturated dicarboxylic acids, for example oxalic, malonic, succinic,maleic, fumaric, phthalic or tetraphthalic; with hydroxycarboxylicacids, for example ascorbic, glycolic, lactic, malic, tartaric or citricacid; with aminoacids, for example aspartic or glutamic acid; withbenzoic acid; or with organic sulfonic acids, such as (C₁-C₄)-alkyl- oraryl-sulfonic acids which are unsubstituted or substituted (for example,by a halogen) such as methane- or p-toluene sulfonic acid.

Esters are formed either using organic acids or alcohols/hydroxides,depending on the functional group being esterified. Organic acidsinclude carboxylic acids, such as alkanecarboxylic acids of 1 to 12carbon atoms which are unsubstituted or substituted (e.g., by halogen),such as acetic acid; with saturated or unsaturated dicarboxylic acid,for example oxalic, malonic, succinic, maleic, fumaric, phthalic ortetraphthalic; with hydroxycarboxylic acids, for example ascorbic,glycolic, lactic, malic, tartaric or citric acid; with aminoacids, forexample aspartic or glutamic acid; with benzoic acid; or with organicsulfonic acids, such as (C₁-C₄)-alkyl- or aryl-sulfonic acids which areunsubstituted or substituted (for example, by a halogen) such asmethane- or p-toluene sulfonic acid. Suitable hydroxides includeinorganic hydroxides, such as sodium hydroxide, potassium hydroxide,calcium hydroxide, aluminium hydroxide. Alcohols include alkanealcoholsof 1-12 carbon atoms which may be unsubstituted or substituted, e.g. bya halogen).

Enantiomers/Tautomers

In all aspects of the present invention previously discussed, theinvention includes, where appropriate all enantiomers and tautomers ofcompounds of formula I or Ia. The man skilled in the art will recognisecompounds that possess an optical properties (one or more chiral carbonatoms) or tautomeric characteristics. The corresponding enantiomersand/or tautomers may be isolated/prepared by methods known in the art.

Stereo and Geometric Isomers

Some of the compounds of the invention may exist as stereoisomers and/orgeometric isomers—e.g. they may possess one or more asymmetric and/orgeometric centres and so may exist in two or more stereoisomeric and/orgeometric forms. The present invention contemplates the use of all theindividual stereoisomers and geometric isomers of those inhibitoragents, and mixtures thereof. The terms used in the claims encompassthese forms, provided said forms retain the appropriate functionalactivity (though not necessarily to the same degree).

The present invention also includes all suitable isotopic variations ofthe agent or a pharmaceutically acceptable salt thereof. An isotopicvariation of an agent of the present invention or a pharmaceuticallyacceptable salt thereof is defined as one in which at least one atom isreplaced by an atom having the same atomic number but an atomic massdifferent from the atomic mass usually found in nature. Examples ofisotopes that can be incorporated into the agent and pharmaceuticallyacceptable salts thereof include isotopes of hydrogen, carbon, nitrogen,oxygen, phosphorus, sulphur, fluorine and chlorine such as ²H, ³H, ¹³C,¹⁴C, ¹⁵N, ¹⁷O, ¹⁸O, ³¹P, ³²P, ³⁵S, ¹⁸F and ³⁶Cl, respectively. Certainisotopic variations of the agent and pharmaceutically acceptable saltsthereof, for example, those in which a radioactive isotope such as ³H or¹⁴C is incorporated, are useful in drug and/or substrate tissuedistribution studies. Tritiated, i.e., ³H, and carbon-14, i.e., ¹⁴C,isotopes are particularly preferred for their ease of preparation anddetectability. Further, substitution with isotopes such as deuterium,i.e., ²H, may afford certain therapeutic advantages resulting fromgreater metabolic stability, for example, increased in vivo half-life orreduced dosage requirements and hence may be preferred in somecircumstances. Isotopic variations of the agent of the present inventionand pharmaceutically acceptable salts thereof of this invention cangenerally be prepared by conventional procedures using appropriateisotopic variations of suitable reagents.

Solvates

The present invention also includes the use of solvate forms of thecompounds of the present invention. The terms used in the claimsencompass these forms.

Polymorphs

The invention furthermore relates to the compounds of the presentinvention in their various crystalline forms, polymorphic forms and(an)hydrous forms. It is well established within the pharmaceuticalindustry that chemical compounds may be isolated in any of such forms byslightly varying the method of purification and or isolation form thesolvents used in the synthetic preparation of such compounds.

Prodrugs

The invention further includes the compounds of the present invention inprodrug form. Such prodrugs are generally compounds of formula I whereinone or more appropriate groups have been modified such that themodification may be reversed upon administration to a human or mammaliansubject. Such reversion is usually performed by an enzyme naturallypresent in such subject, though it is possible for a second agent to beadministered together with such a prodrug in order to perform thereversion in vivo. Examples of such modifications include ester (forexample, any of those described above), wherein the reversion may becarried out be an esterase etc. Other such systems will be well known tothose skilled in the art.

Administration

The pharmaceutical compositions of the present invention may be adaptedfor oral, rectal, vaginal, parenteral, intramuscular, intraperitoneal,intraarterial, intrathecal, intrabronchial, subcutaneous, intradermal,intravenous, nasal, buccal or sublingual routes of administration.

For oral administration, particular use is made of compressed tablets,pills, tablets, gellules, drops, and capsules. Preferably, thesecompositions contain from 1 to 250 mg and more preferably from 10-100mg, of active ingredient per dose.

Other forms of administration comprise solutions or emulsions which maybe injected intravenously, intraarterially, intrathecally,subcutaneously, intradermally, intraperitoneally or intramuscularly, andwhich are prepared from sterile or sterilisable solutions. Thepharmaceutical compositions of the present invention may also be in formof suppositories, pessaries, suspensions, emulsions, lotions, ointments,creams, gels, sprays, solutions or dusting powders.

An alternative means of transdermal administration is by use of a skinpatch. For example, the active ingredient can be incorporated into acream consisting of an aqueous emulsion of polyethylene glycols orliquid paraffin. The active ingredient can also be incorporated, at aconcentration of between 1 and 10% by weight, into an ointmentconsisting of a white wax or white soft paraffin base together with suchstabilisers and preservatives as may be required.

Injectable forms may contain between 10-1000 mg, preferably between10-250 mg, of active ingredient per dose.

Compositions may be formulated in unit dosage form, i.e., in the form ofdiscrete portions containing a unit dose, or a multiple or sub-unit of aunit dose.

Dosage

A person of ordinary skill in the art can easily determine anappropriate dose of one of the instant compositions to administer to asubject without undue experimentation. Typically, a physician willdetermine the actual dosage which will be most suitable for anindividual patient and it will depend on a variety of factors includingthe activity of the specific compound employed, the metabolic stabilityand length of action of that compound, the age, body weight, generalhealth, sex, diet, mode and time of administration, rate of excretion,drug combination, the severity of the particular condition, and theindividual undergoing therapy. The dosages disclosed herein areexemplary of the average case. There can of course be individualinstances where higher or lower dosage ranges are merited, and such arewithin the scope of this invention.

Depending upon the need, the agent may be administered at a dose of from0.01 to 30 mg/kg body weight, such as from 0.1 to 10 mg/kg, morepreferably from 0.1 to 1 mg/kg body weight.

In an exemplary embodiment, one or more doses of 10 to 150 mg/day willbe administered to the patient for the treatment of malignancy.

Combinations

In a particularly preferred embodiment, the one or more compounds of theinvention are administered in combination with one or more otheranticancer agents, for example, existing anticancer drugs available onthe market. In such cases, the compounds of the invention may beadministered consecutively, simultaneously or sequentially with the oneor more other anticancer agents.

Anticancer drugs in general are more effective when used in combination.In particular, combination therapy is desirable in order to avoid anoverlap of major toxicities, mechanism of action and resistancemechanism(s). Furthermore, it is also desirable to administer most drugsat their maximum tolerated doses with minimum time intervals betweensuch doses. The major advantages of combining chemotherapeutic drugs arethat it may promote additive or possible synergistic effects throughbiochemical interactions and also may decrease the emergence ofresistance in early tumor cells which would have been otherwiseresponsive to initial chemotherapy with a single agent. An example ofthe use of biochemical interactions in selecting drug combinations isdemonstrated by the administration of leucovorin to increase the bindingof an active intracellular metabolite of 5-fluorouracil to its target,thymidylate synthase, thus increasing its cytotoxic effects.

Numerous combinations are used in current treatments of cancer andleukemia. A more extensive review of medical practices may be found in“Oncologic Therapies” edited by E. E. Vokes and H. M. Golomb, publishedby Springer.

Beneficial combinations may be suggested by studying the growthinhibitory activity of the test compounds with agents known or suspectedof being valuable in the treatment of a particular cancer initially orcell lines derived from that cancer. This procedure can also be used todetermine the order of administration of the agents, i.e. before,simultaneously, or after delivery. Such scheduling may be a feature ofall the cycle acting agents identified herein.

Natural/Unnatural Amino Acids

In one preferred embodiment of the invention, R⁹, R¹⁰ or R¹¹ may be anatural or unnatural amino acid.

As used herein, the term “unnatural amino acid” refers to a derivativeof an amino acid and may for example include alpha andalpha-disubstituted amino acids, N-alkyl amino acids, lactic acid,halide derivatives of natural amino acids such as trifluorotyrosine,p-Cl-phenylalanine, p-Br-phenylalanine, p-I-phenylalanine,L-allyl-glycine, β-alanine, L-α-amino butyric acid, L-γ-amino butyricacid, L-α-amino isobutyric acid, L-ε-amino caproic acid, 7-aminoheptanoic acid, L-methionine sulfone, L-norleucine, L-norvaline,p-nitro-L-phenylalanine, L-hydroxyproline, L-thioproline, methylderivatives of phenylalanine (Phe) such as 4-methyl-Phe,pentamethyl-Phe, L-Phe (4-amino), L-Tyr (methyl), L-Phe (4-isopropyl),L-Tic (1,2,3,4-tetrahydroisoquinoline-3-carboxyl acid),L-diaminopropionic acid and L-Phe (4-benzyl).

Devices

In one preferred embodiment of the invention, the R⁹, R¹⁰ or R¹¹ groupsallow for the immobilisation of the2-phenylamino-4-heteroaryl-pyrimidine compounds onto a substrate. By wayof example, the R⁹, R¹⁰ or R¹¹ groups may contain chemical functionsthat can be used for covalent attachment to solid phases such asfunctionalised polymers (e.g. agarose, polyacrylamide, polystyrene etc.)as commonly found in matrices (microtitre plate wells, microbeads,membranes, etc.), or used for biochemical assays or affinitychromatography. Alternatively, the R⁹, R¹⁰ or R¹¹ groups may linked toother small molecules (e.g. biotin) or polypeptides (e.g. antigens),which can be used for non-covalent immobilisation through binding to animmobilised receptor (e.g. avidin or streptavidin in the case of biotin,or a specific antibodies in the case of antigens).

Assays

Another aspect of the invention relates to the use of a compound offormula I or Ia as defined hereinabove in an assay for identifyingfurther candidate compounds that influence the activity of one or moreCDK enzymes.

Preferably, the assay is capable of identifying candidate compounds thatare capable of inhibiting one or more of a CDK enzyme, GSK or a PLKenzyme.

More preferably, the assay is a competitive binding assay.

Preferably, the candidate compound is generated by conventional SARmodification of a compound of the invention.

As used herein, the term “conventional SAR modification” refers tostandard methods known in the art for varying a given compound by way ofchemical derivatisation.

Thus, in one aspect, the identified compound may act as a model (forexample, a template) for the development of other compounds. Thecompounds employed in such a test may be free in solution, affixed to asolid support, borne on a cell surface, or located intracellularly. Theabolition of activity or the formation of binding complexes between thecompound and the agent being tested may be measured.

The assay of the present invention may be a screen, whereby a number ofagents are tested. In one aspect, the assay method of the presentinvention is a high through-put screen.

This invention also contemplates the use of competitive drug screeningassays in which neutralising antibodies capable of binding a compoundspecifically compete with a test compound for binding to a compound.

Another technique for screening provides for high throughput screening(HTS) of agents having suitable binding affinity to the substances andis based upon the method described in detail in WO 84/03564.

It is expected that the assay methods of the present invention will besuitable for both small and large-scale screening of test compounds aswell as in quantitative assays.

Preferably, the competitive binding assay comprises contacting acompound of formula I or Ia with a CDK enzyme in the presence of a knownsubstrate of said CDK enzyme and detecting any change in the interactionbetween said CDK enzyme and said known substrate.

A further aspect of the invention provides a method of detecting thebinding of a ligand to a CDK enzyme, said method comprising the stepsof:

-   (i) contacting a ligand with a CDK enzyme in the presence of a known    substrate of said CDK enzyme;-   (ii) detecting any change in the interaction between said CDK enzyme    and said known substrate;    and wherein said ligand is a compound of formula I or Ia.

One aspect of the invention relates to a process comprising the stepsof:

-   (a) performing an assay method described hereinabove;-   (b) identifying one or more ligands capable of binding to a ligand    binding domain; and-   (c) preparing a quantity of said one or more ligands.

Another aspect of the invention provides a process comprising the stepsof:

-   (a) performing an assay method described hereinabove;-   (b) identifying one or more ligands capable of binding to a ligand    binding domain; and-   (c) preparing a pharmaceutical composition comprising said one or    more ligands.

Another aspect of the invention provides a process comprising the stepsof:

-   (a) performing an assay method described hereinabove;-   (b) identifying one or more ligands capable of binding to a ligand    binding domain;-   (c) modifying said one or more ligands capable of binding to a    ligand binding domain;-   (d) performing the assay method described hereinabove;-   (e) optionally preparing a pharmaceutical composition comprising    said one or more ligands.

The invention also relates to a ligand identified by the methoddescribed hereinabove.

Yet another aspect of the invention relates to a pharmaceuticalcomposition comprising a ligand identified by the method describedhereinabove.

Another aspect of the invention relates to the use of a ligandidentified by the method described hereinabove in the preparation of apharmaceutical composition for use in the treatment of proliferativedisorders.

The above methods may be used to screen for a ligand useful as aninhibitor of one or more CDK enzymes.

The present invention is further described by way of example.

EXAMPLES Example 1

Chemical synthesis. The covalent attachment of solubilising moieties canbe achieved in a number of different ways known in the art (Wermuth CG.Preparation of water-soluble compounds by covalent attachment ofsolubilizing moieties. In: Practice of Medicinal Chemistry; AcademicPress: London, UK, 1996; pp 755-776). For example, amino substituents in2-phenylamino-4-heteroaryl-pyrimidine derivatives, or their syntheticprecursors, can be acylated or alkylated with carbonyl functions inappropriate solubilising moiety precursors. Similarly, carbonyl groupsin the 2-phenylamino-4-heteroaryl-pyrimidine derivatives can be aminatedor alkylated with appropriate solubilising moiety precursors. Halogengroups on aromatic C in phenylamino-4-heteroaryl-pyrimidines orprecursors can be substituted through nucleophilic groups insolubilising moiety precursors. Suitable2-phenylamino-4-heteroaryl-pyrimidine precursors may be prepared inaccordance with the teachings of Fischer et al (Fischer P M, Wang S. PCTIntl. Patent Appl. Publ. WO 01/072745; Cyclacel Limited, UK, 2001). Somesynthetic and analytical details for example compounds of the presentinvention (refer Table 1) are given in Example 2 below.

Example 2

[4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine[1]. By condensation betweenNA-[5-(3-dimethylamino-acryloyl)-4-methyl-thiazol-2-yl]-N,N-dimethyl-formamidine(prepared from 1-(2-amino-4-methyl-thiazol-5-yl)-ethanone andN,N-dimethylformamide dimethylacetal) andN-(4-morpholin-4-yl-phenyl)-guanidine nitrate. Yellow solid. M.p.300-304° C.: ¹H-NMR (DMSO-d₆) δ: 2.46 (s, 3H, CH₃), 3.07 (m, 4H, CH₂),3.76 (m, 4H, CH₂), 6.85 (d, 1H, J=5.3 Hz, pyrimidinyl-H), 6.92 (m, 2H,Ph-H), 7.53 (br. s, 1H, NH), 7.67 (m, 2H, Ph-H), 8.30 (d, 1H, J=5.4 Hz,pyrimidinyl-H), 9.25 (br. s, 1H, NH). MS (ESI+) m/z 369 [M+H]⁺(C₁₈H₂₀N₆OS requires 368.5).

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine[2]. By condensation between3-dimethylamino-1-(2,4-dimethyl-thiazol-5-yl)-propenone andN-(4-morpholin-4-yl-phenyl)-guanidine nitrate. Pale solid. ¹H-NMR(CDCl₃) δ: 2.69 (s, 3H, CH₃), 2.70 (s, 3H, CH₃), 3.14 (t, 4H, J=4.8 Hz,CH₂), 3.72 (t, 4H, J=4.9 Hz, CH₂), 6.89 (d, 1H, J=5.1 Hz,pyrimidinyl-H), 6.95 (d, 2H, J=8.8 Hz, Ph-H), 6.98(br. s, 1H, NH), 7.53(d, 2H, J=9.1 Hz, Ph-H), 8.38 (d, 1H, J=5.1 Hz, pyrimidinyl-H). MS(ESI⁺) m/z 368 [M+H]⁺ (C₁₉H₂₁N₅OS requires 367.5).

[4-(2-N-Methylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholinophenyl)amine [3]. By condensation between3-dimethylamino-1-(4-methyl-2-methylaminothiazol-5-yl)-propenone(prepared from 1-(4-methyl-2-methylamino-thiazol-5-yl)-ethanone andN,N-dimethylformamide dimethylacetal) andN-(4-morpholin-4-yl-phenyl)-guanidine nitrate. Pale solid. Anal.RP-HPLC: t_(R) ^(=10.8) min (0-60% MeCN in 0.1% aq CF₃COOH over 20 min,1 mL/min, purity>95%). ¹H-NMR (DMSO-d₆)δ: 2.83 (s, 3H, CH₃), 2.84 (s,3H, CH₃), 3.01 (t, 4H, J=5.0 Hz, CH₂), 3.72 (t, 4H, J=5.0 Hz, CH₂), 6.81(d, 2H, J=5.5 Hz, pyrimidinyl-H), 6.87 (m, 2H, Ph-H), 7.61 (m, 2H,Ph-H), 8.12 (br. s, 1H, NH), 8.26 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 9.19(br. s, 1H, NH). MS (ESI⁺) m/z 383 [M+H]⁺ (C₁₉H₂₂N₆OS requires 382.5).

[4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine[4]. By condensation between3-dimethylamino-1-(2-ethylamino-4-methyl-thiazol-5-yl)-propenone(prepared from 1-(2-ethylamino-4-methyl-thiazol-5-yl)-ethanone andN,N-dimethylformamide dimethylacetal) andN-(4-morpholin-4-yl-phenyl)-guanidine nitrate. Pale solid. Anal.RP-HPLC: t_(R) ^(=19.4) min (0-60% MeCN in 0.1% aq CF₃COOH over 20 min,1 mL/min, purity>95%). ¹H-NMR (DMSO-d₆) δ: 1.16 (t, J=7.5 Hz, 3H, CH₃),2.48 (s, 3H, CH₃), 3.26 (m, 2H, CH₂), 3.01 (t, 4H, J=5.0 Hz, CH₂), 3.72(t, 4H, J=5.0 Hz, CH₂), 6.80 (d, 2H, J=5.5 Hz, pyrimidinyl-H), 6.86 (d,2H, J=9.0 Hz, Ph-H), 7.60 (d, 2H, J=9.0 Hz, Ph-H), 8.25 (d, 1H, J=5.0Hz, pyrimidinyl-H), 8.50 (s, 1H, NH), 9.16 (br. s, 1H, NH).

1-(4-(4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl)-piperazin-1-yl)-ethanone[5]. A solution of 1-fluoro-4-nitrobenzene (6.7 g, 47.5 mmol),1-piperazin-1-yl-ethanone (6.7 g, 52.3 mmol) and K₂CO₃ (6.6 g, 47.5mmol) in DMSO (60 mL) was heated at 100° C. for 18 h. After cooling, themixture was poured into H₂O (0.5 L). The resulting yellow precipitatewas filtered and washed with H₂O to afford of1-[4-(4-nitro-phenyl)-piperazin-1-yl]-ethanone (11.9 g). This waspartially dissolved in EtOH (100 mL) and AcOH (50 mL). The mixture waswarmed to ca. 65° C. and iron powder (−325 mesh, 12.0 g, 215 mmol) wasadded in 1-g portions. The mixture was heated at reflux for 2 hr andfiltered through a pad of Celite. The filtrate was evaporated to leave ablack oil, which was basified by addition of 2 M aq NaOH and wasextracted with EtOAc. The combined organics were washed with brine,dried on MgSO₄, filtered, and evaporated in vacuo to afford1-[4-(4-amino-phenyl)-piperazin-1-yl]-ethanone (6.7 g) as a yellowsolid. An aliquot of this material (2.0 g, 9.12 mmol) was dissolved inEtOH (5 mL) and HNO₃ was added (69% aq soln., 1.26 mL, 19.61 mmol),followed by cyanamide (50% w/v aq soln., 2.48 mL, 31.92 mmol). Theresulting mixture was heated at reflux for 18 h. It was cooled to roomtemperature and poured into Et₂O (100 mL). The ethereal layer wasseparated and concentrated. The resulting precipitate was filtered andwashed with iPrOH/Et₂O, then neat Et₂O. The light brown solid was driedto afford N-[4-(4-acetyl-piperazin-1-yl)-phenyl]-guanidine nitrate (1.2g). This material (1.1g, 2.84 mmol) was dissolved in 2-methoxyethanol(14 mL) and K₂CO₃ (0.79 g, 5.68 mmol) was added, followed by3-dimethylamino-1-(2,4-dimethyl-thiazol-5-yl)-propenone (0.60 g, 2.84mmol). The resulting mixture was heated at 115° C. for 18 h. It wascooled and concentrated. The residue was purified by SiO₂ chromatography(9:1 EtOAc/2 M NH₃ in MeOH) and recrystallisation from iPr₂O/MeOH toafford the title compound (930 mg) as a light brown solid. ¹H-NMR(CDCl₃), 2.15 (s, 3H, CH₃), 2.69 (s, 3H, CH₃), 2.71 (s, 3H, CH₃), 3.12(t, 2H, J=5.4 Hz, CH₂), 3.15 (t, 2H, J=5.4 Hz, CH₂), 3.63 (t, 2H, J=5.4Hz, CH₂), 3.79 (t, 2H, J=5.4 Hz, CH₂), 6.90 (d, 1H, J=5.4 Hz,pyrimdinyl-H), 6.96 (m, 2H, Ph-H), 6.98 (br. s, 1H, NH), 7.54 (m, 2H,Ph-H), 8.39 (d, 1H, J=5.4 Hz, pyrimidinyl-H). MS (ESI⁺) m/z 409.6(C₂₁H₂₄N₆OS requires 408.5).

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-piperazin-1-yl-phenyl)-amine[6]. To a solution of1-(4-{4-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-ethanone(0.67 g, 1.64 mmol) in EtOH (3 mL) was added 2 M aq HCl (25 mL) in asteady stream. The mixture was heated at reflux for 1 h, cooled, andbasified by addition of solid Na₂CO₃. The product was extracted withEtOAc. The combined organics were washed with brine, dried on Na₂SO₄,filtered, and evaporated to afford the title compound (580 mg) as ayellow solid. ¹H-NMR (CDCl₃) ^(TM): 2.62 (s, 3H, CH₃), 2.63 (s, 3H,CH₃), 2.99 (m, 4H, CH₂), 3.06 (m, 4H, CH₂), 6.81 (d, 1H, J=5.4 Hz,pyrimidinyl-H), 6.89 (m, 3H, Ph-H, NH), 7.44 (m, 2H, Ph-H), 8.31 (d, 1H,J=5.4 Hz, pyrimidinyl-H). MS (ESI+) m/z 367 (C₁₉H₂₂N₆S requires 366.5).

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4′-2″-ethoxylethanolpiperazino)-phenyl]-amine[7]. A mixture of[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-piperazin-1-yl-phenyl)-amine(0.1 g, 0.27 mmol), 2-(2-chloro-ethoxy)-ethanol (35 μL, 0.33 mmol), NaI(49 mg, 0.33 mmol), and K₂CO₃ (37 mg, 0.27 mmol) in MeCN (2 mL) in asealed tube was heated at 170° C. for 15 min in a microwave-reactor(SmithCreator, Personal Chemistry Ltd). The solvent was evaporated todryness and the residue was purified by SiO₂ chromatography (98:2 to95:5 EtOAc/2 M NH₃ in MeOH) to afford the title compound (78 mg) asyellow foam. ¹H-NMR (CDCl₃) δ: 2.69 (s, 3H, CH₃), 2.71 (s, 3H, CH₃),2.80-2.91 (m, 6H, CH₂), 3.30 (m, 4H, CH₂), 3.67 (m, 2H, CH₂), 3.73 (m,2H, CH₂), 3.79 (m, 2H, CH₂), 6.89 (d, 1H, J=5.4 Hz, pyrimidinyl-H), 6.97(m, 3H, Ph-H & NH), 7.52 (m, 2H, Ph-H), 8.02 (br. s, 1H, OH), 8.38 (d,1H, J=5.4 Hz, pyrimidinyl-H). MS (ESI⁺) m/z 456 (C₂₃H₃₀N₆O₂S requires454.6).

3-(4-4-[4-(2,44-Dimethyl-thiazol-4-yl)-pyrimidin-2-ylamino]-phenyl)-piperazin-1-yl)-propan-1-ol[8]. Yellow solid. ¹H-NMR (CDCl₃) δ: 2.69 (s, 3H, CH₃), 2.71 (s, 3H,CH₃), 2.75 (m, 2H, CH₂), 3.21 (m, 2H, CH₂), 3.84 (t, 2H, J=5.1 Hz, CH₂),6.89 (d, 1H, J=5.4 Hz, pyrimidinyl-H), 6.95 (m, 2H, Ph-H), 6.98 (br. s,1H, NH), 7.51 (m, 2H, Ph-H), 8.38 (d, 1H, J=5.4 Hz, pyrim-H). MS (ESI+):m/z 425.8 (C₂₂H₂₈N₆OS requires 424.6).

2-(4-{4-[4-(2,4-Dimethyl-thiazol-4-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-ethanol[9]. Yellow solid. ¹H-NMR (CDCl₃) δ: 2.55 (t, 2H, J=5.4 Hz, CH₂), 2.62(m, 10H, CH₃ & CH₂), 3.12 (t, 4H, J=4.9 Hz, CH₂), 3.60 (t, 2H, J=5.4 Hz.CH₂), 6.81 (d; 1H, J=5.4 Hz, pyrimidinyl-H), 6.88 (m, 2H, Ph-H), 7.05(br. s, 1H, NH), 7.45 (m, 2H, Ph-H), 8.30 (d, 1H, J=5.1 Hz,pyrimidinyl-H). MS (ESI+) m/z 411.7 (C₂₁H₂₆N₆OS requires 410.5).

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4-methanesulonyl-piperazin-1-yl)-phenyl]-amine[10]. A mixture of[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-piperazin-1-yl-phenyl)-amine(86 mg, 0.23 mmol) in anhydrous CH₂Cl₂ (2 mL) was added Et₃N (39 μL,0.28 mmol). After cooling to 0° C., methanesulfonyl chloride (22 μL,0.28 mmol) was added dropwise. After 15 min stirring, the reactionmixture was warmed to room temperature and stirring was continued for 18h. After evaporation, the residue was purified by SiO₂ chromatography(98:2 to 95:5 EtOAc/2 M NH₃ in MeOH) to afford the title compound (61mg) as a yellow solid. ¹H-NMR (CDCl₃) δ: 2.69 (s, 3H, CH₃), 2.71 (s, 3H,CH₃), 2.84 (s, 3H, CH₃), 3.26 (t, 4H, J=5.1 Hz, CH₂), 3.41 (t, 4H, J=5.1Hz, CH₂), 6.91 (d, 1H, J=5.1 Hz, pyrimidinyl-H), 6.98 (d, 2H, J=8.8 Hz,Ph-H), 7.10 (br. s, 1H, NH), 7.56 (d, 2H, J=8.8 Hz, Ph-H), 8.30 (d, 1H,J=5.1 Hz, pyrimidinyl-H). MS (ESI⁺) m/z 446 (C₂₀H₂₄N₆O₂S₂ requires444.6).

[4-(4-Benzyl-piperazin-1-yl)-phenyl]-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-amine[11]. 4-(4-Benzyl-piperazin-1-yl)-phenylamine (2.17 g, 8.12 mmol) waspartially dissolved in EtOH (5 mL) and HNO₃ (69% aq soln., 1.05 mL,16.32 mmol) was added dropwise, followed by cyanamide (50% aq soln.,1.13 mL, 16.32 mmol). The mixture was heated fo 18 h at reflux. Afterworking up N-[4-(4-benzyl-piperazin-1-yl)-phenyl]-guanidine nitrate(1.16 g) was obtained as a purple solid. A mixture of this material(2.66 mmol),3-dimethylamino-1-(4-methyl-2-methylaminothiazol-5-yl)-propenone (0.60g, 2.66 mmol), and K₂CO₃ (0.74 g, 5.32 mmol) in 2-methoxyethanol (15 mL)was heated at 120° C. for 18 h. After cooling, it was poured into EtOAc(100 mL) and filtered through a pad of silica. The filtrate wasevaporated and the residue was purified by SiO₂ chromatography(heptane/EtOAc) to afford the title compound (442 mg) as a light tansolid. ¹H-NMR (CD₃OD) δ: 2.44 (s, 3H, CH₃), 2.56-2.58 (m, 4H, CH₂), 2.91(s, 3H, CH₃), 3.09 (m, 4H, CH₂), 3.51 (s, 2H, CH₂), 6.70 (d, 1H, J=5.6Hz, pyrimidinyl-H), 6.87 (m, 2H, Ph-H), 7.22 (m, 1H, Ph-H), 7.27 (m, 4H,Ph-H), 7.43 (m, 2H, Ph-H), 8.15 (d, 1H, J=5.4 Hz, pyrimidinyl-H). MS(ESI⁺) m/z 473.2 (C₂₆H₂₉N₇S requires 471.6).

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4-methyl-piperazin-1-yl)-phenyl]-amine[12]. By condensation between3-dimethylamino-1-(2,4-dimethyl-thiazol-5-yl)-propenone andN-[4-(4-methyl-piperazin-1-yl)-phenyl]-guanidine nitrate. Light yellowsolid. ¹H-NMR (CDCl₃), 2.37 (s, 3H, CH₃), 2.61 (m, 4H, CH₂), 2.69 (s,3H, CH₃), 2.70 (s, 3H, CH₃), 3.20 (m, 4H, CH₂), 6.88 (d, 1H, J=5.1 Hz,pyrimidinyl-H), 6.94 (s, 1H, NH), 6.96 (d, 2H, J=8.8 Hz, Ph-H), 7.51 (d,2H, J=8.8 Hz, Ph-H), 8.38 (d, 1H, J=5.1 Hz, pyrimidinyl-H).

3-Amino-N-(4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl)-propionamide[13]. A mixture of[4-(2-amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(3-nitro-phenyl)-amine(0.12 g, 0.37 mmol), Boc-βAla-OH (0.18 g, 0.93 mmol),1,3-diisopropylcarbodiimide (0.07 mL, 0.45 mmol) and4-N,N-dimethylaminopyridine (36 mg, 0.3 mmol) in of dry DMF (2 mL) wasstirred at room temperature for 24 h. The reaction mixture was pouredinto ice water and extracted with EtOAc. The organics were combined andwashed with brine, filtered, and dried on MgSO₄. The solvent wasevaporated to give brown residue, which was purified by SiO₂chromatography (1:1 EtOAc/PE) to afford({4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-ylcarbamoyl}-methyl)-carbamicacid tert-butyl ester as light yellow solid. Anal. RP-HPLC: t_(R)^(=19.5) min (0-60% MeCN in 0.1% aq CF₃COOH over 20 min, 1 mL/min,purity>93%). ¹H-NMR (DMSO-d₆) δ: 1.11 (s, 9H, CH₃), 2.54 (s, 3H, CH₃),3.62 (m, 2H, CH₂), 5.38 (m, 2H, CH₂), 7.06 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 7.46 (m, 1H, Ph-H), 7.72 (m, 1H, Ph-H), 8.15 (m, 1H,Ph-H), 8.45 (d, 1H, J=5.2 Hz, pyrimidinyl-H), 8.77 (s, 1H, NH). Asolution of this material (97 mg, 0.19 mmol) in dioxane (5 mL) wastreated with CF₃COOH (1 ml). After stirring at room temperature for 22h, the reaction mixture was evaporated and purified by preparativeRP-HPLC (0-60% MeCN in 0.1% aq CF₃COOH over 40 min, 9 mL/min) to affordthe titled compound (34 mg) as a light yellow solid. Anal. RP-HPLC:t_(R) ^(=14.0) min (0-60% MeCN in 0.1% aq CF₃COOH over 20 min, 1 mL/min,purity>93%). ¹H-NMR (CD₃OD) δ: 2.64 (s, 3H, CH₃), 3.30 (m, 2H, CH₂),3.33 (m, 2H, CH₂), 7.14 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 7.52 (t, 1H,J=8.2 Hz, Ph-H), 7.63 (m, 1H, Ph-H), 7.96 (m, 1H, Ph-H), 8.46 (d, 1H,J=5.5 Hz, pyrimidinyl-H), 8.88 (s, 1H, NH). MS (ESi⁺) m/z 400.6(C₁₇H₁₇N₇O₃S requires 399.4).

(2S)-2-Amino-3-hydroxy-N-(4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide[14]. From Boc-L-Ser-OH. Pale solid. Anal. RP-HPLC: t_(R) ^(=13.7) min(0-60% MeCN in 0.1% aq CF₃COOH over 20 min, 1 mL/min, purity>93%).¹H-NMR (CD₃OD) δ: 2.45 (s, 3H, CH₃), 3.65-3.77 (m, 3H, CH & CH₂), 3.95(br. s, 1H, OH), 7.03 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 7.36 (t, 1H,J=6.5 Hz, Ph-H), 7.63 (m, 1H, Ph-H), 7.97 (m, 1H, Ph-H), 8.41 (d, 1H,J=5.5 Hz, pyrimidinyl-H), 8.63 (s, 1H, NH).

(2R,3R)-2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide[15]. From Boc-D-Thr-OH. Yellow solid. ¹H-NMR (CD₃OD) δ: 1.35 (d, 3H,J=6.1 Hz, CH₃), 2.66 (s, 1H, CH), 3.95 (d, 1H, J=5.4 Hz, CH), 7.17 (d,1H, J=5.4 Hz, pyrimidinyl-H), 7.51 (m, 1H, Ph-H), 7.97 (m, 1H, Ph-H),8.51 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 8.92 (m, 1H, Ph-H).

(2R)-2-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide[16]. From Boc-D-Abu-OH. Yellow solid. ¹H-NMR (DMSO-d₆) δ: 0.93 (t, 3H,J=7.6 Hz, CH₃), 0.94 (m, 2H, CH₂), 1.60 (s, 3H, CH₃), 3.00 (t, 1H, J=6.9Hz, CH), 6.10 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 6.44 (m, 1H, Ph-H), 6.77(m, 1H, Ph-H), 6.87 (m, 1H, Ph-H), 7.42 (d, 1H, J=5.5 Hz, pyrimidinyl-H)and 7.86 (br. s, 1H, NH). MS (ESI⁺) m/z 414.6 (C₁₈H₁₉N₇O₃S requires413.5).

(2S,3S)-2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide[17]. From Boc-L-Thr-OH. Yellow solid. ¹H-NMR (CD₃OD) δ: 1.19 (d, 3H,J=6.6 Hz, CH₃), 2.63 (s, 3H, CH₃), 3.89 (m, 1H, CH), 4.10 (m, 1H, CH),7.20 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 7.55 (t, 1H, J=8.0 Hz, Ph-H),7.81 (d, 1H, J=8.5 Hz, Ph-H), 8.16 (d, 1H, J=8.5 Hz, Ph-H), 8.58 (d, 1H,J=5.5 Hz, pyrimidinyl-H), 8.80 (s, 1H, Ph-H) and 10.17 (s, 1H, NH).

4-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide[18]. Yellow solid. ¹H-NMR (CD₃OD) δ: 1.87 (m, 2H, CH₂), 2.52 (s, 3H,CH₃), 2.56 (m, 2H, CH₂), 2.84 (m, 2H, CH₂), 7.17 (d, 1H, J=5.3 Hz,pyrimidinyl-H), 7.55 (t, 1H, J=8.3 Hz, Ph-H), 7.79 (m, 1H, Ph-H), 8.13(m, 1H, Ph-H), 8.54 (d, 1H, J=5.3 Hz, pyrimidinyl-H), 8.83 (s, 1H, Ph-H)and 10.12 (s, 1H, NH).

3-Amino-N-{4-methyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide[19]. Yellow solid. ¹H-NMR (DMSO-d₆) d: 2.57 (m, 2H, CH₂), 2.71 (s, 3H,CH₃), 2.92 (m, 2H, CH₂), 3.02 (m, 4H, CH₂), 3.73 (m, 4H, CH₂), 6.87 (d,2H, J=8.0 Hz, Ph-H), 6.95 (d, 1H, J=5.3 Hz, pyrimidinyl-H), 7.61 (d, 1H,J=8.0 Hz, Ph-H), 8.38 (d, 1H, J=5.5 Hz, pyrimidinyl-H) and 9.32 (s, 1H,NH). MS (ESI⁺) m/z 439 (C₂₁H₂₅N₇O₂S requires 439.5).

3-Bromo-N-{5-[2-(4-fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamide[20]. A solution of[4-(2-amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-fluoro-phenyl)-amine(0.3 g, 1.0 mmol) in DMF (2 mL) was cooled on an ice bath and wastreated with 2-bromopropionyl chloride (0.17 g, 1.0 mmol). Aftercompletion of the addition, the reaction mixture was allowed to stir atroom temperature for 18 h. It was poured into ice water and wasextracted with CH₂Cl₂. The organics were combined, washed with brine,dried on MgSO₄, and the solvent was evaporated to leave a brown residue.This was purified by SiO₂ chromatography (1:1 EtOAc/PE) to afford thetitle compound as a light yellow solid. Anal. RP-HPLC: t_(R) ^(=17.1)min (0-60% MeCN in 0.1% aq CF₃COOH over 20 min, 1 mL/min, purity>93%).¹H-NMR (DMSO-d₆) δ: 1.99 (m, 2H, CH₂), 2.68 (s, 3H, CH₃), 4.65 (m, 2H,CH₂), 7.02 (d, 1H, J=5.2 Hz, pyrimidinyl-H), 7.11 (m, 2H, Ph-H), 7.62(m, 2H, Ph-H), 8.19 (d, 1H, J=5.5 Hz, pyrimidinyl-H).

N-{5-[2-(4-Fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-morpholin-4-yl-propionamide[21]. A solution of3-bromo-N-{5-[2-(4-fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamide(20 mg, 0.046 mmol) and morpholine (8 μL, 0.092 mmol,) in DMF (2 mL) wasstirred at room temperature for 2 h. The reaction mixture was purifiedby preparative RP-HPLC (0-60% MeCN in 0.1% aq CF₃COOH over 40 min, 9mL/min) to afford the title compound as a pale solid. Anal. RP-HPLC:t_(R) ^(=13.3) min (0-60% MeCN in 0.1% aq CF₃COOH over 20 min, 1 mL/min,purity>93%). ¹H-NMR (CD₃OD) δ: 2.66 (s, 3H, CH₃), 3.23 (m, 2H, CH₂),3.33 (m, 2H, CH₂), 3.41 (m, 4H, CH₂), 3.87 (m, 2H, CH₂), 4.13 (m, 2H,CH₂), 7.04-7.09 (m, 3H, pyrimidinyl-H & Ph-H), 7.68 (m, 2H, Ph-H), 8.39(d, 1H, J=5.5 Hz, pyrimidinyl-H). MS (ESI+) m/z 443.3 (C₂₁H₂₃FN₆O₂Srequires 442.5).

N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-3-morpholin-4-yl-propionamide[22]. Yellow solid. ¹H-NMR (CD₃OD) δ: 2.64 (s, 3H, CH₃), 3.23 (m, 2H,CH₂), 3.33 (m, 2H, CH₂), 3.41 (m, 4H, CH₂), 3.87 (m, 2H, CH₂), 4.13 (m,2H, CH₂), 7.04-7.09 (m, 3H, pyrimidinyl-H & Ph-H), 7.68 (m, 2H, Ph-H),8.39 (d, 1H, J=5.5 Hz, pyrimidinyl-H). MS (ESI⁺) m/z 443.3 (C₂₁H₂₃FN₆O₂Srequires 442.5).

N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-3-(4-methyl-piperazin-1-yl)-propionamide[23]. Yellow solid. ¹H-NMR (CD₃OD) δ: 2.94 (s, 3H, CH₃), 3.01 (m, 2H,CH₂), 3.24-3.43 (m, 4H, CH₂), 3.65 (m, 2H, CH₂), 7.14 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 7.52 (m, 1H, Ph-H), 7.86 (d, 1H, J=8.0 Hz, Ph-H), 7.99(d, 1H, J=8.0 Hz, Ph-H), 8.44 (m, 1H, Ph-H) and 8.79 (d, 1H, J=5.5 Hz,pyrimidinyl-H). MS (ESI⁺) m/z 485 (C₂₂H₂₆N₈O₃S requires 482.6).

2-Chloro-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-acetamide[24]. A solution of[4-(2-amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(3-nitro-phenyl)-amine(0.33 g, 1.0 mmol,) in dry DMF (3 mL) was cooled on an ice-water bath.Chloroacetyl chloride (0.22 g, 2.0 mmol) and pyridine (80 μL) wereadded. After stirring at room temperature for 18 h, the reaction mixturewas concentrated, poured into ice water and extracted with CH₂Cl₂. Theorganic phases were combined, washed with brine, dried on MgSO₄ andevaporated to dryness. The resulting greenish residue was purified bySiO₂ chromatography (1:1 EtOAc/PE) to afford the title compound as agray solid. Anal. RP-HPLC: t_(R) ^(=20.6) min (0-60% MeCN in 0.1% aqCF₃COOH over 20 min, 1 mL/min, purity>97%). ¹H-NMR (DMSO-d₆)δ: 2.45 (s,3H, CH₃), 4.12 (s, 2H, CH₂), 7.03 (d, 1H, J=5.2 Hz, pyrimidinyl-H), 7.42(m, 1H, Ph-H), 7.63 (m, 1H, Ph-H), 8.01 (m, 1H, Ph-H), 8.41 (d, 1H,J=5.2 Hz, pyrimidinyl-H), 8.64 (s, 1H, Ph-H).

2-Chloro-N-{5-[2-(3-chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide[25]. Brown solid. ¹H-NMR (DMSO-d₆) δ: 2.65 (s, 3H, CH₃), 4.42 (s, 2H,CH₂), 7.01 (m, 1H, Ph-H), 7.25 (mg 1H, Ph-H), 7.61 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 7.98 (s, 1H, Ph-H), 8.75 (d, 1H, J=5.5 Hz,pyrimidinyl-H) and 10.09 (br. s, 1H, NH).

2-Chloro-N-{5-[2-(3-methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide[26]. Brown solid. ¹H NMR (DMSO-d₆) δ: 2.58 (s, 3H, CH₃), 3.78 (s, 3H,CH₃), 4.36 (s, 2H, CH₂), 6.51 (m, 1H, Ph-H), 7.08 (d, 1H, J=5.5,pyrimidinyl-H), 7.14 (t, 1H, J=8.0 Hz, Ph-H), 7.23 (m, 1H, Ph-H), 7.59(s, 1H, Ph-H) and 8.45 (d, 1H, J=5.5 Hz, pyrimidinyl-H).

2-Chloro-N-{5-[2-(4-dimethylamino-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide[27]. Yellow solid. ¹H-NMR (CD₃OD) δ: 2.57 (s, 3H, CH₃), 3.23 (s, 6H,CH₃), 4.22 (s, 2H, CH₂), 7.06 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 7.57 (d,2H, J=9.5 Hz, Ph-H), 7.73 (d, 2H, J=9.5 Hz, Ph-H), 8.14 (br. s, 1H, NH)and 8.35 (d, 1H, J=5.5 Hz, pyrimidinyl-H).

4-({4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-ylcarbamoyl}-methyl)-piperazine-1-carboxylicacid tert-butyl ester [28]. A solution of2-chloro-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-acetamide(40 mg, 0.1mmol) in DMF (2 mL) was cooled on an ice bath.Piperazine-1-carboxylic acid tert-butyl ester (40 mg, 0.21 mmol) wasadded. After stirring at room temperature for 16 h, the reaction mixturewas purified by preparative RP-HPLC (0-60% MeCN in 0.1% aq CF₃COOH over40 min, 9 mL/min) to afford the title compound (20 mg) as a light yellowsolid. Anal. RP-HPLC: t_(R) ^(=16.9) min (0-60% MeCN in 0.1% aq CF₃COOHover 20 min, 1 mL/min, purity>97%). ¹H-NMR (CD₃OD) δ: 2.65 (s, 3H, CH₃),2.87 (m, 4H, CH₂), 3.36 (m, 4H, CH₂), 4.66 (s, 2H, CH₂), 7.71 (m, 1H,pyrimidinyl-H), 7.89 (t, 1H, J=8.1 Hz, Ph-H), 8.15 (m, 1H, Ph-H), 7.42(m, 1H, Ph-H), 7.67 (m, 2H, pyrimidinyl-H & Ph-H).

N-{5-[2-(4-Dimethylamino-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-2-[2-(2-hydroxy-ethoxy)-ethylamino]-acetamide[29]. Anal. RP-HPLC: t_(R) ^(=10.52) min (0-60% MeCN in 0.1% aq CF₃COOHover 20 min, 1 mL/min, purity>97%). ¹H-NMR (CD₃OD) δ: 3.28 (s, 3H, CH₃),3.41 (s, 6H, CH₃), 4.04 (m, 2H, CH₂), 4.28 (m, 2H, 4H, CH₂), 4.34 (m,2H, CH₂), 4.50 (m, 2H, CH₂), 4.94 (br. s, 2H, CH₂), 7.92 (d, 1H, J=5.5Hz, pyrimidinyl-H), 8.00 (d 2H, J=90 Hz, Ph-H), 8.41 (m, 1H, J=9.0 Hz,Ph-H), 8.87 (br. s, 1H, NH/OH), 9.31 (d, 1H, J=5.5 Hz, pyrimidinyl-H).

6-[5-(2-Oxo-hexahydro-thieno[3,4-d]imidazol-4-yl)-pentanoylamino]-hexanoicacid(2-{4-methyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-thiazol-2-ylcarbamoyl}-ethyl)-amide[30]. A solution of3-amino-N-{4-methyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide(75 mg, 0.17 mmol) in DMF (1 mL) was treated withsuccinimidyl-6-(biotinamido)hexanoate (32 mg, 0.085 mmol). Afterstirring at room temperature for 3 h, the reaction mixture was purifiedby preparative RP-HPLC (0-60% MeCN in 0.1% aq CF₃COOH over 40 min, 9mL/min) to afford the title compound as an orange solid. Anal. RP-HPLC:t_(R) ^(=13.2) min (0-60% MeCN in 0.1% aq CF₃COOH over 20 min, 1 mL/min,purity>97%). MS (ESI+) m/z 776 (C₃₇H₅₀N₁₀O₅S₂ requires 778.9).

N-{5-[2-(4-Fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-methanesulfonamide-[31].This compound was prepared from[4-(2-amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-fluoro-phenyl)-amineby treatment with methylsulfonyl chloride and Et₃N in DMF. Gray solid;¹H-NMR (DMSO-d₆) δ: 3.31 (s, 3H, CH₃), 3.63 (s, 3H, CH₃), 7.32 (m, 1H,pyrimidinyl-H), 7.42 (m, 2H, Ph-H), 8.11 (m, 2H, Ph-H), 8.63 (d, 1H,J=5.0 Hz, pyrimidinyl-H).

N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-methanesulfonamide [32]. A mixture of[4-(2-amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(3-nitro-phenyl)-amine(1.0 mmol, 0.33 g) and methylsulfonyl chloride (2.0 mmol, 0.22 g) in dryDMF (2 mL) was added Et₃N (0.28 mL). The reaction mixture was stirred atroom temperature for 20 h. After cooling, the mixture was diluted withEtOAc, washed with brine, and dried over MgSO₄. The solvent wasevaporated and the residue was purified by preparative RP-HPLC using agradient from 10-70% MeCN in 0.1% aq CF₃COOH over 40 min. The titlecompound was obtained as an orange solid. Anal. RP-HPLC: t_(R) ^(=17.4)min (0-60% MeCN in 0.1% aq CF₃COOH over 20 min, 1 mL/min, purity>97%).¹H-NMR (DMSO-d₆) o: 3.10 (s, 3H, CH₃), 3.25 (s, 3H, CH₃), 7.05 (d, 1H,J=5.2 Hz, pyrimidinyl-H), 7.42 (m, 1H, Ph-H), 7.63 (m, 1H, Ph-H), 7.98(m, 1H, Ph-H), 8.21(d, 1H, J=5.2 Hz, pyrimidinyl-H), 8.42 (s, 1H, Ph-H),9.18 (s, 1H, NH).

2-Chloro-N-{5-[2-(4-fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide[33]. This compound was prepared from[4-(2-amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-fluoro-phenyl)-amine.¹H-NMR (DMSO-d₆) δ: 2.94 (s, 3H, CH₃), 4.75 (s, 2H, CH₂), 7.44(m, 3H,pyrimidinyl-H & Ph-H), 8.09 (m, 2H, Ph-H), 8.28 (s, 1H, NH), 8.80 (d,1H, J=5.2 Hz, pyrimidinyl-H).

2-Chloro-N-{5-[2-(4-chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide[34]. This compound was prepared by chloroacetylation of[4-(2-amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-chloro-phenyl)-amine.Brown solid. ¹H-NMR (DMSO-d₆) δ: 2.65 (s, 3H, CH₃), 4.42 (s, 2H, CH₂),7.01 (m, 1H, Ph-H), 7.25 (m, 1H, Ph-H), 7.61 (d, 1H, J=5.5,pyrimidinyl-H), 7.98 (s, 1H, Ph-H), 8.75 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 10.09 (br. s, 1H, NH).

N-{5-[2-(4-Chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-morpholin-4-yl-propionamide[35]. By treatment of3-chloro-N-{5-[2-(4-chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamidewith morpholine. Anal. RP-HPLC: t_(R) ^(=12.7) min (10-70% MeCN,purity>95%). ¹H-NMR (CDCl₃) δ: 1.50 (m, 2H, CH₂), 2.52 (s, 3H, CH₃),3.05-3.78 (m, 8H, CH₂), 3.81 (m, 2H, CH₂), 7.12 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 7.30 (d, 2H, J=7.0 Hz, Ph-H), 7.80 (d, 2H, J=7.0 Hz,Ph-H), 8.51 (d, 1H, J=5.0 Hz, pyrimidinyl-H), 9.80 (brs, 1H, NH).

N-{5-[2-(4-Chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-(2-diethylamino-ethylamino)-propionamide[36]. By treatment of3-bromo-N-{5-[2-(4-chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamidewith N′,N′-diethyl-ethane-1,2-diamine. Anal. RP-HPLC: t_(R) ^(=11.8) min(10-70% MeCN, purity>97%). ¹H-NMR (DMSO-D₆) δ: 1.20 (t, 6H, J=7.0 Hz,CH₃), 1.53 (d, 2H, J=6.5 Hz, CH₂), 2.52 (s, 6H, CH₃), 3.18 (m, 4H, CH₂),3.28 (m, 4H, CH₂), 7.13 (d, 1H, J=5.0 Hz, pyrimidinyl-H), 7.30 (m, 2H,Ph-H), 7.81 (m, 2H, Ph-H), 8.51 (d, 1H, J=5.0 Hz, pyrimidinyl-H), 9.82(brs, 1H, NH).

N-{5-[2-(4-Chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-(2-morpholin-4-yl-ethylamino)-propionamide[37]. By treatment of3-bromo-N-{5-[2-(4-chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamidewith 2-morpholin-4-yl-ethylamine (or3-amino-N-{5-[2-(4-chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamidewith 4-(2-chloro-ethyl)-morpholine. Anal. RP-HPLC: t_(R) ^(=11.5) min(10-70% MeCN, purity>97%). ¹H-NMR (DMSO-D₆) δ 1.52 (d, 2H, J=7.0 Hz,CH₂), 2.48 (m, 2H, CH₂), 2.52 (s, 3H, CH₃), 3.05-3.11 (m, 4H, CH₂),3.25-3.28 (m, 6H, CH₂), 4.08 (m, 2H, CH₂), 7.13 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 7.29 (m, 2H, Ph-H), 7.82 (m, 2H, Ph-H), 8.51 (d, 1H,J=5.5 Hz, pyrimidinyl-H), 9.82 (brs, 1H, NH).

N-{5-[2-(4-Methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-morpholin-4-yl-propionamide[38]. By treatment of3-bromo-N-{5-[2-(4-methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamidewith morpholine. Anal. RP-HPLC: t_(R) ^(=12.7) min (0-60% MeCN,purity>90%). ¹H-NMR (CDCl₃) δ: 1.20 (m, 2H, CH₂), 2.54-2.63 (m, 7H, CH₃and CH₂), 3.34 (m, 2H, CH₂), 3.80 (m, 5H, CH₃ and CH₂), 4.03 (m, 2H,CH₂), 6.87-6.92 (m, 3H, pyrimidinyl-H and Ph-H), 7.17 (brs, 1H, NH),7.53 (m, 2H, Ph-H), 8.35 (m, 1H, pyrimidinyl-H), 10.33 (brs, 1H, NH).

N-{5-[2-(3-Methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-morpholin-4-yl-propionamide[39]. By treatment of3-bromo-N-{5-[2-(3-methoxyphenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamidewith morpholine. Anal. RP-HPLC: t_(R) ^(=13.6) min (0-60% MeCN,purity>94%). ¹H-NMR (DMSO-D₆) δ: 1.20 (m, 2H, CH₂), 2.48 (m, 4H, CH₂),2.58 (s, 3H, CH₃), 3.41-3.57 (m, 6H, CH₂), 3.79 (s, 3H, CH₃), 6.52 (d,1H, J=7.0 Hz, Ph-H), 7.07 (d, 1H, J=5.4 Hz, pyrimidinyl-H), 7.15 (t, 1H,J=7.3 Hz, Ph-H), 7.22 (m, 1H, Ph-H), 7.62 (brs, 1H, Ph-H), 8.46 (d, 1H,J=5.5 Hz, pyrimidinyl-H), 9.58 (brs, 1H, NH). MS (ESI⁺) m/z 456.01[M+H]⁺ (C₂₂H₂₆N₆SO₃ requires 454.55).

N-{5-[2-(4-Methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-(4-methyl-piperazin-1-yl)-propionamide[40]. By treatment of3-bromo-N-{5-[2-(4-methoxyphenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamidewith 1-methyl-piperazine. Anal. RP-HPLC: t_(R) ^(=13.0) min (0-60% MeCN,purity>94%). ¹H-NMR (DMSO-D₆) δ: 1.17 (m, 2H, CH₂), 2.11 (m, 2H, CH₂),2.48 (m, 4H, CH₂), 2.57 (s, 3H, CH₃), 3.28 (s, 3H, CH₃), 3.30 (m, 4H,CH₂), 3.72 (s, 3H, CH₃), 6.85 (m, 2H, Ph-H), 6.97 (m, 1H,pyrimidinyl-H), 7.63 (m, 2H, Ph-H), 8.38 (d, 1H, J=5.1 Hz,pyrimidinyl-H). MS (ESI⁺) m/z 468.57 [M+H]⁺ (C₂₃H₂₆N₇SO₂ requires467.59).

N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-acetamide[45]. By condensation between3-dimethylamino-1-(2,4-dimethyl-thiazol-5-yl)-propenone andN-(4-acetamidophenyl)-guanidine nitrate. Pale solid. Mp. 219-220° C.¹H-NMR (DMSO-D₆) δ: 2.00 (s, 3H, CH₃), 2.61 (s, 3H, CH₃), 2.64 (s, 3H,CH₃), 7.04 (d, 1H, J=4.9 Hz, pyrimidinyl-H), 7.48 (d, 2H, J=8.8 Hz,Ph-H), 7.64 (d, 2H, J=8.8 Hz, Ph-H), 8.47 (d, 1H, J=5.4 Hz,pyrmidinyl-H), 9.58 (s, 1H, NH), 9.82 (s, 1H, NH). MS (ESI+) m/z 340.02[M+H]⁺ (C₁₇H₁₇N₅OS requires 339.42).

N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-N-methyl-acetamide[48]. By condensation reaction of3-dimethylamino-1-(2,4-dimethyl-thiazol-5-yl)-propenone andN-(4-N-methylacetamidophenyl)-guanidine nitrate. ¹H-NMR (DMSO-D₆) δ:1.75 (s, 3H, CH₃), 2.62 (s, 3H, CH₃), 2.64 (s, 3H, CH₃), 3.11 (s, 3H,CH₃), 7.11 (d, 1H, J=4.9 Hz, pyrimidinyl-H), 7.24 (d, 2H, J=7.8 Hz,Ph-H), 7.83 (d, 2H, J=7.8 Hz, Ph-H), 8.53 (d, 1H, J=4.9 Hz,pyrimidinyl-H), 9.83 (brs, 1H, NH). MS (ESI⁺) m/z 354.88 [M+H]⁺(C₁₈H₁₉N₅OS requires 353.44).

1-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-propan-2-ol[49]. By treatment of[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-piperazin-1-yl-phenyl)-aminewith 1-chloro-2-propanol. ¹H-NMR (CDCl₃) δ: 1.10 (d, 3H, J=6.0 Hz, CH₃),2.26-2.33 (m, 2H, CH₂), 2.49-2.53 (m, 2H, CH₂), 2.61 (s, 3H, CH₃), 2.63(s, 3H, CH₃), 2.76-2.80 (m, 2H, CH₂), 3.07-3.13 (m, 4H, CH₂), 3.83 (m,1H, CH), 6.81 (d, 1H, J=4.4 Hz, pyrimidinyl-H), 6.88 (d, 2H, J=8.8 Hz,Ph-H), 7.02 (brs, 1H, OH), 7.44 (d, 2H, J=8.8 Hz, Ph-H), 8.30 (d, 1H,J=4.4 Hz, pyrimidinyl-H).

2-Chloro-N-{4-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-acetamide[50]. By treatment of[4-(2,4-dimethylthiazol-5-yl)-pyrimidin-2-yl]-(4-aminophenyl)-amine withchloroacetyl chloride. Mp. 217-219° C. ¹H-NMR (DMSO-D₆) δ: 2.61 (s, 3H,CH₃), 2.64 (s, 3H, CH₃), 4.22 (s, 2H, CH₂), 7.05 (d, 1H, J=5.4 Hz,pyrimidinyl-H), 7.50 (d, 2H, J=8.8 Hz, Ph-H), 7.70 (d, 2H, J=8.8 Hz,Ph-H), 8.49 (d, 1H, J=4.9 Hz, pyrimidinyl-H), 9.65 (s, 1H, NH), 10.20(s, 1H, NH). MS (ESI⁺) m/z 374.47 [M+H]⁺ (C₁₇H₁₆ClN₅OS requires 373.86).

N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-2-morpholin-4-yl-acetamide[51]. By treatment of2-chloro-N-{4-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-acetamidewith morpholine. ¹H-NMR (DMSO-D₆) δ: 2.61 (s, 3H, CH₃), 2.64 (s, 3H,CH₃), 3.09 (s, 2H, CH₂), 3.27-3.31 (m, 4H, CH₂), 3.62-3.64 (m, 4H, CH₂),7.04 (d, 1H, J=5.4 Hz, pyrimidinyl-H), 7.54 (d, 2H, J=8.8 Hz, Ph-H),7.67 (d, 2H, J=8.8 Hz, Ph-H), 8.48 (d, 1H, J=4.9 Hz, pyridinyl-H), 9.59(s, 1H, NH). MS (ESI⁺) m/z 425.01 [M+H]⁺ (C₂₁H₂₄N₆O₂S requires 424.52).

N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-2-[1,2,4]triazol-1-yl-acetamide[52]. By treatment of2-chloro-N-{4-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-acetamidewith 1H-[1,2,4]triazole. ¹H-NMR (DMSO-D₆) δ: 2.61 (s, 3H, CH₃), 2.63 (s,3H, CH₃), 5.10 (s, 2H, CH₂), 7.05 (d, 1H, J=5.4 Hz, pyrimidinyl-H), 7.50(d, 2H, J=8.3 Hz, pyrimidinyl-H), 7.69 (d, 2H, J=8.9 Hz, Ph-H), 7.98 (s,1H, Aryl-H), 8.48 (d, 1H, J=4.9 Hz, pyrimidinyl-H), 8.53 (s, 1H,Aryl-H), 9.62 (brs, 1H, NH), 10.30 (brs, 1H, NH). MS (ESI+) m/z 406.97(C₁₉H₁₈N₈OS requires 406.47).

N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-2-pyrrolidin-1-yl-acetamide[53]. By treatment of2-chloro-N-{4-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-acetamidewith pyrrolidine. ¹H-NMR (DMSO-D₆) δ: 1.74 (m, 4H, CH₂), 2.58 (m, 4H,CH₂), 2.61 (s, 3H, CH₃), 2.64 (s, 3H, CH₃), 3.20 (s, 2H, CH₂), 7.04 (d,1H, J=5.4 Hz, pyrimidinyl-H), 7.55 (d, 2H, J=8.8 Hz, Ph-H), 7.66 (d, 2H,J=8.8 Hz, Ph-H), 8.48 (d, 1H, J=5.4 Hz, pyrimidinyl-H), 9.55 (s, 1H,NH), 9.58 (s, 1H, NH). MS (ESI⁺) m/z 406.97 [M+H]⁺ (C₂₁H₂₄N₆OS requires408.52).

N-{4-[4-(2,4-Dimethyl-thiazol-4-yl)-pyrimidin-2-ylamino]-phenyl}-2-imidazol-1-yl-acetamide[54]. By treatment of2-chloro-N-{4-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-acetamidewith 1H-imidazole. ¹H-NMR (DMSO-D₆) δ: 2.61 (s, 3H, CH₃), 2.63 (s, 3H,CH₃), 4.86 (s, 2H, CH₂), 6.88 (s, 1H, Aryl-H), 7.04 (d, 1H, J=5.9 Hz,pyrimidinyl-H), 7.15 (s, 1H, Aryl-H), 7.50 (d, 2H, J=7.8 Hz, Ph-H), 7.62(s, 1H, Aryl-H), 7.68 (d, 2H, J=7.8 Hz, Ph-H), 8.48 (d, 1H, J=5.4 Hz;pyrimidinyl-H); 9.60 (s, 1H, NH), 10.18 (brs, 1H, NH). MS (ESI⁺) m/z406.02 [M+H]⁺ (C₂₀H₁₉N₇OS requires 405.48).

3-[4-(4-Methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenol[55]. A solution of morpholine-4-carbonitrile (10 g, 89.19 mmol) in EtOH(65 mL) was cooled on an ice bath. Anhydrous NH₃ was bubbled through thesolution for 5 min, followed by hydrogen sulfide. Soon after theintroduction of H₂S a white precipitate was observed. After the additionof both gases for 45 min NH₃ addition was stopped and H₂S continued fora further 15 minutes. The resulting precipitate was collected, washedwith cold water, MeOH and dried under high vacuum to affordmorpholine-4-carbothioic acid amide (12.83 g). Mp. 173-174° C. ¹H-NMR(DMSO-D₆) δ: 3.54 (t, 4H, J=4.9 Hz, CH₂), 3.70 (m, 4H, CH₂), 7.46 (brs,2H, NH₂). This was converted first to1-(4-methyl-2-morpholin-4-yl-thiazol-5-yl)-ethanone with3-bromo-pentane-2,4-dione, then with dimethoxymethyl-dimethyl-amine to3-dimethylamino-1-(4-methyl-2-morpholin-4-yl-thiazol-5-yl)-propenone inthe usual manner. The latter enaminone was condensed withN-(3-hydroxy-phenyl)-guanidine nitrate to afford the title compound as apale solid. Mp. 227-229 C. ¹H-NMR (DMSO-D₆) δ: 2.49 (s, 3H, CH₃), 3.46(t, 4H, J=4.4 Hz, CH₂), 3.71 (t, 4H, J=4.4 Hz, pyrimidinyl-H), 6.34 (d,1H, J=8.8 Hz, Ph-H), 6.91 (d, 1H, J=5.4 Hz, pyrimidinyl-H), 7.03 (t, 1H,J=7.8 Hz, Ph-H), 7.20-7.22 (m, 2H, Ph-H), 8.34 (d, 1H, J=5.4 Hz,pyrimidinyl-H), 9.17 (s, 1H, OH/NH), 9.32 (s, 1H, NH/OH). MS (ESI⁺) m/z370.10 [M+H]⁺ (C₁₈H₁₉N₅O₂S requires 369.44).

[4-(4-Methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine[56]. By treatment of3-dimethylamino-1-(4-methyl-2-morpholino-thiazol-5-yl)-propenone andN-(4-morpholinophenyl)-guanidine nitrate. Pale solid. Mp. 229-231° C.¹H-NMR (DMSO-D₆) δ: 2.48 (s, 3H, CH₃), 3.02 (t, 4H, J=4.0 Hz, CH₂), 3.46(t, 4H, J=4.0 Hz, CH₂), 3.70-3.73 (m, 8H, CH₂), 6.86 (d, 1H, J=5.4 Hz,pyrimidinyl-H), 6.89 (d, 2H, J=9.3 Hz, Ph-H), 7.60 (d, 2H, J=8.8 Hz,Ph-H), 8.30 (d, 1H, J=5.4 Hz, pyrimidinyl-H), 9.22 (s, 1H, NH). MS(ESI⁺) m/z 439.03 [M+H]⁺ (C₂₂H₂₆N₆O₂S requires 438.55).

N,N-Dimethyl-N′-[4-[4-methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-yl]-benzene-1,4-diamine[57]. By treatment of3-dimethylamino-1-(4-methyl-2-morpholino-thiazol-5-yl)-propenone andN-(4-N,N-dimethylaminophenyl)-guanidine nitrate. Yellow solid. ¹H-NMR(DMSO-D₆) δ: 2.48 (s, 3H, CH₃), 2.82 (s, 6H, CH₃), 3.46 (t, 4H, J=4.9Hz, pyrimidinyl-H), 3.70 (t, 4H, J=4.9 Hz, CH₂), 6.70 (d, 2H, J=8.8 Hz,Ph-H), 6.82 (d, 1H, J=5.4 Hz, pyrimidinyl-H), 7.53 (d, 2H, J=8.8 Hz,Ph-H), 8.27 (d, 1H, J=5.4 Hz, pyrimidinyl-H), 9.09 (s, 1H, NH). MS(ESI⁺) m/z 397.03 [M+H]⁺ (C₂₀H₂₄N₆OS requires 396.51).

2-{4-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-ethanol[59]. By condensation between3-dimethylamino-1-(4-methyl-2-methylamino-thiazol-5-yl)-propenone andN-[4-(2-hydroxy-ethyl)-phenyl]-guanidine nitrate. Pale solid. Mp216-218° C. Anal. RP-HPLC: t_(R)=9.1 min (10-70% MeCN, purity>95%).¹H-NMR (DMSO-d₆) δ: 2.46 (s, 3H, CH₃), 3.05 (s, 3H, CH₃), 3.55 (m, 2H,CH₂), 4.58 (m, 2H, CH₂), 6.85 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 7.08 (m,2H, Ph-H), 7.64 (m, 2H, Ph-H), 8.0 (m, 1H, OH), 8.29 (d, 0.1H, J=5.5 Hz,pyrimidinyl-H), 9.30 (brs, 1H, NH): MS (ESI⁺) m/z 363.99 [M+H]⁺Na(C₁₇H₁₉N₅SONa requires 364.43).

1-(4-{4-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-ethanone[61]. By condensation between3-dimethylamino-1-(4-methyl-2-methylamino-thiazol-5-yl)-propenone andN-[4-(4-acetyl-piperazin-1-yl)-phenyl]-guanidine nitrate. Yellow solid.Mp 213-214° C. Anal. RP-HPLC: t_(R)=8.8 min (10-70% MeCN, purity>95%).¹H-NMR (DMSO-d₆) δ: 2.43 (s, 3H, CH₃), 3.02 (s, 3H, CH₃), 3.23 (s, 3H,CH₃), 2.99 (m, 2H, CH₂), 3.06 (t, 2H, CH₂), 3.57 (t, 4H, CH₂), 6.82 (d,1H, J=6.0 Hz, pyrimidinyl-H), 6.89 (d, 2H, J=9.0 Hz, Ph-H), 7.62 (d, 2H,J=9.5 Hz, Ph-H), 8.26 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 9.18 (s, 1H,NH). MS (ESI+) m/z 424.07 [M+H]⁺ (C₂₁H₂₅N₇OS requires 423.54).

[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-(4-piperazin-1-yl-phenyl)-amine[62]. By hydrolysis of1-(4-{4-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-ethanonein 2 M aq HCl. Yellow solid. Anal. RP-HPLC: t_(R)=8.8 min (10-70% MeCN,purity>95%). ¹H-NMR (DMSO-d₆) δ: 2.45 (3, 3H, CH₃), 2.83 (t, 4H, J=5.9Hz, CH₂), 2.85 (d, 3H, J=4.9 Hz, CH₂), 2.95 (t, 4H, J=4.9 Hz, CH₂), 6.81(d, 1H, J=5.4 Hz, pyrimidinyl-H), 6.85 (d, 2H, J=9.3 Hz, Ph-H), 7.58 (d,2H, J=8.8 Hz, Ph-H), 7.99 (m, 1H, NH), 8.26 (d, 1H, J=5.4 Hz,pyrimidinyl-H), 9.14 (brs, 1H).

N-{3-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-acetamide[63]. By condensation of3-dimethylamino-1-(2-methylamino-4-methyl-thiazol-5-yl)-propenone andN-(3-guanidino-benzyl)-acetamide nitrate. Yellow solid. Mp 253-255° C.Anal. RP-HPLC: t_(R)=11.3 min (10-70% MeCN, purity>95%): ¹H NMR (DMSO):δ 1.86 (s, 3H, CH₃), 2.46 (s, 3H, CH₃), 2.85 (s, 2H, CH₂), 3.09 (s, 3H,CH₃), 6.82 (d, 1H, J=8.0 Hz, ph-H), 6.88 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 7.2 (t, 1H, J=8.0 Hz, Ph-H), 7.60 (d, 1H, J=8.0 Hz,Ph-H), 7.73 (s, 1H, Ph-H), and 8.32 (d, 1H, J=5.5 Hz, pyrimidinyl-H). MS(ESI⁺) m/z 391.55 [M+Na] (C₁₈H₂₀N₆OSNa requires 391.46).

N-(3-[4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl)-acetamide[64]. By condensation of3-dimethylamino-1-(2-ethylamino-4-methyl-thiazol-5-yl)-propenone andN-(3-guanidino-benzyl)-acetamide nitrate. Yellow solid. Anal. RP-HPLC:t_(R)=12.7 min (0-60% MeCN, purity>95%). ¹H-NMR (CD₃OD) δ: 1.17 (t, 3H,J=7.5 Hz, CH₃), 1.98 (s, 3H, CH₃), 2.51 (s, 3H, CH₃), 3.36 (q, 2H, J=7.1Hz, CH₂), 4.39 (s, 2H, CH₂), 6.92 (m, 2H, pyrimidinyl-H and Ph-H), 7.25(t, 1H, J=7.6 Hz, Ph-H), 7.49 (m, 1H, Ph-H), 7.79 (sbr, 1H, Ph-H), 8.25(d, 1H, J=5.5 Hz, pyrimidinyl-H). MS (ESI⁺) m/z 383.46 [M+H]⁺(C₁₉H₂₂N₆OS requires 382.48).

(3-Aminomethyl-phenyl)-[4-(2-ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-amine[65]. By hydrolysis ofN-{3-[4-(2-ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-acetamide.Yellow solid. Mp 290-292° C. Anal. RP-HPLC: t_(R)=10.6 min (10-70% MeCN,purity>95%). ¹H-NMR (DMSO-D₆) δ: 1.31 (t, 3H, J=7.0 Hz, CH₃), 2.64 (s,3H, CH₃), 3.54 (m, 2H, CH₂), 4.11 (m, 2H, CH₂), 7.14 (d, 1H, J=6.0 Hz,pyrimidinyl-H), 7.22 (d, 1H, J=8.0 Hz, Ph-H), 7.45 (t, 1H, J=8.0 Hz,Ph-H), 7.74 (d, 1H, J=8.0 Hz, Ph-H), 7.95 (s, 1H, Ph-H), 8.53 (d, 1H,J=6.0 Hz, pyrimidinyl-H). MS (ESI⁺) m/z 341.20 [M+H]⁺ (C₁₇H₂₀N₆Srequires 340.45).

N-{3-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-acetamide[66]. By treatment of3-dimethylamino-1-(2,4-dimethyl-thiazol-5-yl)-propenone andN-(3-guanidino-benzyl)-acetamide nitrate. Yellow solid. Mp 206-207° C.Anal. RP-HPLC: t_(R)=13.6 min (0-60% MeCN, purity>95%). ¹H-NMR (DMSO-D₆)δ: 1.99 (s, 3H, CH₃), 2.65 (s, 3H, CH₃), 2.68 (s, 3H, CH₃), 4.38 (s, 2H,CH₂), 6.94 (d, 1H, J=7.5 Hz, Ph-H), 7.01 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 7.26 (d, 1H, J=8.0 Hz, Ph-H), 7.56 (d, 1H, J=7.5 Hz,Ph-H), 7.70 (s, 1H, Ph-H), 8.40 (d, 1H, J=5.5 Hz, pyrimidinyl-H). MS(ESI⁺) m/z 345.42 [M+H]⁺ (C₁₈H₁₉N₅OS requires 353.44).

(3-Aminomethyl-phenyl)-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-amine[67]. By treatment ofN-{3-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-acetamidewith HCl/MeOH. Yellow solid. Mp 287-289° C. Anal. RP-HPLC: t_(R)=10.1min (0-60% MeCN, purity 92%). ¹H-NMR (DMSO-D₆) δ: 2.68 (s, 3H, CH₃),3.17 (s, 3H, CH₃), 4.17 (m, 2H, CH₂), 7.23 (d, 1H, J=6.0 Hz,pyrimidinyl-H), 7.27 (d, 1H, J=8.0 Hz, Ph-H), 7.50 (t, 1H, J=8.0 Hz,Ph-H), 7.70 (d, 1H, J=7.5 Hz, Ph-H), 7.75 (s, 1H, Ph H), 8.44 (d, 1H,J=6.0 Hz, pyrimidinyl-H). MS (ESI⁺) m/z 327.37 [M+H]⁺ (C₁₆H₁₈N₆Srequires 326.42).

{3-[4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-methanol[68]. By condensation of3-dimethylamino-1-(2-ethylamino-4-methyl-thiazol-5-yl)-propenone andN-(3-hydroxymethyl-phenyl)-guanidine nitrate. Yellow solid. Anal.RP-HPLC: t_(R)=12.6 min (0-60% MeCN, purity>95%). ¹H-NMR (CD₃OD) δ: 1.28(t, 3H, J=7.3 Hz, CH₃), 2.52 (s, 3H, CH₃), 3.35 (q, 2H, J=7.1 Hz, CH₂),4.63 (s, 2H, CH₂), 5.49 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 7.63 (d, 1H,J=7.6 Hz, Ph-H), 7.27 (t, 1H, J=7.9 Hz, Ph-H), 7.52 (m, 1H, Ph-H), 7.79(sbr, 1H, Ph-H), 8.26 (d, 1H, J=5.5 Hz, pyrimidinyl-H). MS (ESI⁺) m/z346.44 [M+H]⁺ (C₁₇H₁₉N₅OS requires 341.43).

[4-(4-Methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-yl]-(3-nitro-phenyl)-amine[71]. By condensation of 3-dimethylamino-1-(4-methyl2-morpholin-4-yl-thiazol-5-yl)-propenone andN-(3-nitro-phenyl)-guanidine nitrate. Yellow solid. Anal. RP-HPLC:t_(R)=16.7 min (10-70% MeCN, purity>95%). ¹H-NMR (DMSO-D₆) δ: 2.51 (s,3H, CH₃), 3.50 (t, 4H, J=4.5 Hz, CH₂), 3.72 (t, 4H, J=4.5 Hz, CH₂), 7.06(d, 1H, J=5.5 Hz, pyrimidinyl-H), 7.55 (t, 1H, J=8.5 Hz, Ph-H), 7.77 (d,1H, J=8.5 Hz, Ph-H), 7.97 (d, 1H, J=8.5 Hz, Ph-H), 8.44 (d, 1H, J=5.5Hz, pyrimidinyl-H), 9.03 (s, 1H, Ph-H), 10.06 (sbr, 1H, NH). MS (ESI⁺)m/z 399.20 [M+H]⁺ (C₁₈H₁₈N₆O₃S requires 398.44).

{2-Chloro-5-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-methanol[72]. By condensation of3-dimethylamino-1-(2,4-dimethyl-thiazol-5-yl)-propenone andN-(4-chloro-3-hydroxymethyl-phenyl)-guanidine nitrate. Yellow solid. Mp245-246° C. Anal. RP-HPLC: t_(R)=14.6 min (10-70% MeCN, purity>95%).¹H-NMR (DMSO-D₆) δ: 2.62 (s, 3H, CH₃), 2.63 (s, 3H, CH₃), 4.53 (d, 2H,J=5.5 Hz, CH₂), 5.34 (m, 1H, OH), 7.08 (d, 1H, J=5.5 Hz, pyrimidinyl-H),7.29 (m, 1H, Ph-H), 7.73 (m, 1H, Ph-H), 7.94 (s, 1H, Ph-H), 8.51 (d, 1H,J=5.5 Hz, pyrimidinyl-H), 9.78 (s, 1H, NH). MS (ESI⁺) m/z 347.11 [M+H]⁺(C₁₆H₁₅ClN₄OS requires 346.84).

{2-Chloro-5-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-methanol[73]. By condensation of3-dimethylamino-1-(2-methyamino-4-methyl-thiazol-5-yl)-propenone andN-(4-chloro-3-hydroxymethyl-phenyl)-guanidine nitrate. Yellow solid. Mp191-193° C. Anal: RP-HPLC: t_(R)=11.5 min (10-70% MeCN, purity>90%).¹H-NMR (DMSO-D₆)δ: 2.46 (s, 3H, CH₃), 3.08 (s, 3H, CH₃), 4.52 (d, 2H,J=6.0 Hz, CH₂), 5.29 (m, 1H, OH), 6.89 (d, 1H, J=5.5 Hz, pyrimidinyl-H),7.25 (d, 1H, J=8.5 Hz, Ph-H), 7.73 (m, 1H, Ph-H), 7.94 (s, 1H, Ph-H),8.03 (sbr, 1H, NH), 8.32 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 9.55 (s, 1H,NH). MS (ESI⁺) m/z 361.89 [M] (C₁₆H₁₆ClN₅OS requires 361.85).

[4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-methanesulonyl-phenyl)-amine[76]. By condensation ofN′-[5-(3-dimethylamino-acryloyl)-4-methyl-thiazol-2-yl]-N,N-dimethyl-formamidineand N-(4-methanesulfonyl-phenyl)-guanidine nitrate. Yellow solid. Anal.RP-HPLC: t_(R)=13.2 min (0-60% MeCN, purity>97%). ¹H-NMR (DMSO-d₆) δ:1.98 (s, 3H, CH₃), 2.54 (s, 3H, CH₃), 7.06 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 7.80 (m, 2H, Ph-H), 8.00 (m, 2H, Ph-H), 8.45 (d, 1H,J=5.5 Hz, pyrimidinyl-H), 10.05 (sbr, 2H, NH₂). MS (ESI⁺) m/z 362.38[M+H]⁺ (C₁₅H₁₅N₅O₂S₂ requires 361.44).

[4-(2-Methoxy-ethoxy)-3-nitro-phenyl]-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-amine[77]. By alkylation of[4-(2-aminomethyl-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-fluoro-3-nitrophenyl)-aminewith 2-methoxy-ethanol. Yellow solid. Anal. RP-HPLC: t_(R)=12.8 min(10-70% MeCN, purity>90%). ¹H-NMR (DMSO-D₆) δ: 2.41 (s, 3H, CH₃), 2.86(d, 3H, J=4.5 Hz, CH₃), 3.24 (s, 3H, CH₃), 3.66 (m, 2H, CH₂), 4.23 (m,2H, CH₂), 6.93 (d, 1H, J=6.0 Hz, pyrimidinyl-H), 7.32 (d, 1H, J=5.0 Hz,Ph-H), 7.79 (m, 1H, Ph-H), 8.08 (d, 1H, J=5.0 Hz, Ph-H), 8.35 (d, 1H,J=5.0 Hz, pyrimidinyl-H), 8.54 (m, 1H, NH), 9.68 (s, 1H, NH). MS (ESI⁺)m/z 417.08 [M+H]⁺ (C₁₈H₂₀N₆O₄S requires 416.46).

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[3-(2-morpholin-4-yl-ethoxymethyl)-phenyl]-amine[81]. By alkylation of{3-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-methanolwith 4-(2-chloro-ethyl)-morpholine. Yellow solid. Anal. RP-HPLC:t_(R)=8.5 min (10-70% MeCN, purity>95%). ¹H-NMR (DMSO-D₆)δ: 2.56 (s, 3H,CH₃), 2.57 (s, 3H, CH₃), 2.63 (m, 2H, CH₂), 3.58 (m, 4H, J=4.5 Hz,CH₂x2), 4.14 (t, 2H, J=7.5 Hz, CH₂), 4.58 (d, 2H, J=5.0 Hz, CH₂), 5.28(t, 1H, J=5.5 Hz, NH), 7.06 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 7.26 (m,2H, Ph-H), 7.36 (s, 1H, Ph-H), 7.42 (m, 1H, Ph-H), 8.43 (d, 1H, J=5.5Hz, pyrimidinyl-H), 9.12 (sbr, 1H, Ph-H). MS (ESI⁺) m/z 426.46 [M+H]⁺(C₂₂H₂₇N₅O₂S requires 425.55).

C,C,C-Trifluoro-N-{3-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-methanesuljonamide[82]. By treatment of(3-aminomethyl-phenyl)-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-aminewith trifluoro-methanesulfonyl chloride. Yellow solid. Anal. RP-HPLC:t_(R)=11.6 min (0-60% MeCN, purity 90%). ¹H-NMR (CD₃OD) δ: 2.53 (s, 3H,CH₃), 2.97 (s, 3H, CH₃), 4.39 (s, 2H, CH₂), 6.94 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 7.01 (d, 1H, J=7.5 Hz, Ph-H), 7.31 (d, 1H, J=8.0 Hz,Ph-H), 7.60 (d, 1H, J=7.5 Hz, Ph-H), 7.67 (s, 1H, Ph-H), 8.28 (d, 1H,J=5.5 Hz, pyrimidinyl-H). MS (ESI+) m/z 459.33 [M+H]⁺ (C₁₇H₁₇F₃N₆O₂Srequires 458.48).

N-{3-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-methanesulfonamide[83]. By treatment of(3-aminomethyl-phenyl)-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-aminewith methane-sulfonyl chloride. Yellow solid. Anal. RP-HPLC: t_(R)=12.8min (0-60% MeCN, purity>95%). ¹H-NMR (CD₃OD) δ: 2.53 (s, 3H, CH₃), 2.88(s, 3H, CH₃), 2.98 (s, 3H, CH₃), 4.28 (s, 2H, CH₂), 6.94 (d, 1H, J=5.5Hz, pyrimidinyl-H), 7.02 (d, 1H, J=7.5 Hz, Ph-H), 7.29 (t, 1H, J=8.0 Hz,Ph-H), 7.52 (d, 1H, J=8.0 Hz, Ph-H), 7.90 (s, 1H, Ph-H), 7.98 (s, 1H,NH), 8.28 (d, 1H, J=5.5 Hz, pyrimidinyl-H).

[4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(3-methanesulonyl-phenyl)-amine[84]. By condensation ofN′-[5-(3-dimethylamino-acryloyl)-4-methyl-thiazol-2-yl]-N,N-dimethyl-formamidineand N-(3-methanesulfonyl-phenyl)-guanidine nitrate. Yellow solid. Anal.RP-HPLC: t_(R)=13.1 min (0-60% MeCN, purity>97%). ¹H-NMR (DMSO-d₆) δ:2.55 (s, 3H, CH₃), 3.19 (s, 3H, CH₃), 6.97 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 7.47 (m, 1H, Ph-H), 7.54 (t, 1H, J=7.5 Hz, Ph-H), 8.08(m, 1H, Ph-H), 8.34 (brs, 1H, Ph-H), 8.40 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 9.86 (sbr, 2H, NH₂). MS (ESI⁺) m/z 362.38 [M+H]⁺(C₁₅H₁₅N₅O₂S₂ requires 361.44).

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-methanesulonyl-phenyl)-amine[85]. By condensation of3-dimethylamino-1-(2,4-dimethyl-thiazol-5-yl)-propenone andN-(4-methanesulfonyl-phenyl)-guanidine nitrate. Yellow solid. Anal.RP-HPLC: t_(R)=16.6 min (0-60% MeCN, purity>97%). ¹H-NMR (DMSO-d₆)δ:2.65 (s, 3H, CH₃), 2.66 (s, 3H, CH₃), 3.15 (s, 3H, CH₃), 7.22 (d, 1H,J=5.5 Hz, pyrimidinyl-H), 7.84 (d, 2H, J=9.0 Hz, Ph-H), 8.03 (d, 2H,J=9.0 Hz, Ph-H), 8.61 (d, 1H, J=5.5 Hz, pyrimidinyl-H), 10.23 (sbr, 1H,NH). MS (ESI) m/z 361.17 [M+H]+(C₁₆H₁₆N₄O₂S₂ requires 361.46).

3,4-Dimethyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-3H-thiazol-2-one[92]. Methylammonium N-methylthio-carbamate (13.1 g, 0.105 mol; preparedfrom methylamine and carbonyl sulfide as described, Y. Gelernt et al.1974, J. Chem. Soc. Perkin Trans. 1, 2610) was partially dissolved inMeOH (150 mL). 3-Chloro-pentane-2,4-dione (14.9 mL, 0.125 mol) was addeddrop-wise at room temperature, producing a gradual exotherm to 40° C.After stirring at room temperature for 1 h, the solvent was removed invacuo. The residue was treated with H₂O (50 mL) and was extracted withCH₂Cl₂ (3×50 mL). The combined organic fractions were washed (brine),dried (Na₂SO₄), filtered, and evaporated in vacuo to an amber-colouredoil. This was purified by chromatography (300 g SiO₂, eluting with 1:1heptane/Et₂O to obtain non-cyclized adduct, then Et₂O to obtain5-acetyl-3,4-dimethyl-3H-thiazol-2-one, which was recrystallized fromEtOH as colourless needles (14.2 g). ¹H-NMR (CDCl₃): δ 2.34 (s, 3H),2.59 (s, 3H), 3.33 (s, 3H). IR (ATR): 1655 and 1621 cm⁻¹ (CO str).

5-Acetyl-3,4-dimethyl-3H-thiazol-2-one (4.64 g, 27.10 mmol) anddimethylformamide dimethyl acetal (8.4 mL, 59.62 mmol) were mixed in adry, argon-flushed flask, and heated at 100° C. for 3 h. The mixture wascooled, producing some precipitation, which was enhanced by the additionof an equal volume of Et₂O. The resulting orange solid was filtered andwashed with Et₂O to give 2.73g of5-(3-dimethylamino-acryloyl)-3,4-dimethyl-3H-thiazol-2-one. ¹H-NMR(d₆-DMSO): δ 2.52 (s, 3H), 2.82 (bs, 3H), 3.11 (bs, 3H), 3.22 (s, 3H),5.10 (d, 1H, J=12.2 Hz), 7.61 (d, 1H, J=11.7 Hz). IR (ATR): 1669 and1630 cm⁻¹ (CO str).

Condensation between5-(3-dimethylamino-acryloyl)-3,4-dimethyl-3H-thiazol-2-one andN-(4-morpholin-4-yl-phenyl)-guanidine nitrate afforded the titlecompound. Anal. RP-HPLC: t_(R)=17.5 min (0-60% MeCN in 0.1% aq CF₃COOHover 20 min, 1 mL/min, purity>95%). ¹H-NMR (DMSO-d₆) δ: 2.48 (3H, s,CH₃), 3.03 (4H, m, 2×morph-NCH₂), 3.08 (3H, s, CH₃), 3.72 (4H, m,2×morph-OCH₂), 6.85 (1H, d, J=5.2, pyrim-H), 6.89 (2H, d, J=9.2, 2×ArH),7.57 (2H, d, J=9.2, 2×ArH), 8.36 (1H, d, J=5.2, pyrim-H) and 9.35 (1H,s, NH). MS (ESI⁺) m/z 384[M+H]⁺ (C₁₉H₂₁N₅O₂S requires 383.5).

3,4-Dimethyl-5-{2-[4-(4-methyl-piperazin-1-yl)-phenylamino]-pyrimidin-4-yl}-3H-thiazol-2-one[93]. This compound was prepared by condensation between5-(3-dimethylamino-acryloyl)-3,4-dimethyl-3H-thiazol-2-one andN-[4-(4-methyl-piperazin-1-yl)-phenyl]-guanidine nitrate. Pale solid.Anal. RP-HPLC: t_(R)=10.9 min (0-60% MeCN in 0.1% aq CF₃COOH over 20min, 1 mL/min, purity>97%). ¹H-NMR (CDCl₃)δ: 2.42 (m, 4H, CH₂), 2.53 (s,3H, CH₃), 3.04 (m, 4H, CH₂), 3.28 (s, 3H, CH₃), 6.84 (d, 1H, J=5.5 Hz,pyrimidinyl-H), 6.86 (d, 2H, J=9.0 Hz, Ph-H), 7.54 (d, 2H, J=9.0 Hz,Ph-H), 8.35 (d, 1H, J=5.5 Hz, pyrimidinyl-H), and 9.33 (s, 1H, NH).

Example 3

Kinase assays. The compounds from Example 2 above were investigated fortheir ability to inhibit the enzymatic activity of various proteinkinases. This was achieved by measurement of incorporation ofradioactive phosphate from ATP into appropriate polypeptide substrates.Recombinant protein kinases and kinase complexes were produced orobtained commercially. Assays were performed using 96-well plates andappropriate assay buffers (typically 25 mM β-glycerophosphate, 20 mMMOPS, 5 mM EGTA, 1 mM DTT, 1 mM Na₃VO₃, pH 7.4), into which were added2-4 μg of active enzyme with appropriate substrates. The reactions wereinitiated by addition of Mg/ATP mix (15 mM MgCl₂+100 μM ATP with 30-50kBq per well of [γ-³²P]-ATP) and mixtures incubated as required at 30°C. Reactions were stopped on ice, followed by filtration through p81filterplates or GF/C filterplates (Whatman Polyfiltronics, Kent, UK).After washing 3 times with 75 mM aq orthophosphoric acid, plates weredried, scintillant added and incorporated radioactivity measured in ascintillation counter (TopCount, Packard Instruments, Pangbourne, Berks,UK). Compounds for kinase assay were made-up as 10 mM stocks in DMSO anddiluted into 10% DMSO inrassay buffer. Data was analysed usingcurve-fitting software (GraphPad Prism version 3.00 for Windows,GraphPad Software, San Diego Calif. USA) to determine IC₅₀ values(concentration of test compound which inhibits kinase activity by 50%).

CDK 7 and 9 assays. CTD peptide substrate(biotinyl-Ahx-(Tyr-Ser-Pro-Thr-Ser-Pro-Ser)₄-NH₂; 1-2 mg/mL) andrecombinant human CDK7/cyclin H, CDK9/cyclin T1, or CDK9/cyclin K (0.5-2μg) were incubated for 45 min at 30° C. in the presence of varyingamounts of test compound in 20 mM MOPS pH 7.2, 25 mM β-glycerophosphate,5 mM EGTA, 1 mM DTT, 1 mM sodium vanadate, 15 mM MgCl₂, and 100 μM ATP(containing a trace amount of ³²PγATP) in a total volume of 25 μL in a96-well microtiter plate. The reaction was stopped by placing the plateon ice for 2 min. Avidin (50 μg) was added to each well, and the platewas incubated at room temp for 30 min. The samples were transferred to a96-well P81 filter plate, and washed (4×200 μL per well) with 75 mMphosphoric acid. Microscint 40 scintillation liquid (50 μL) was added toeach well, and the amount of ³²P incorporation for each sample wasmeasured using a Packard Topcount microplate scintillation counter.

Aurora-A (human) kinase assay. This was achieved by measurement ofincorporation of radioactive phosphate from ATP into Kemptide substrate(LRRASLG), upon phosphorylation by commercially obtained aurora-Akinase. Assays were performed using 96-well plates and appropriate assaybuffers (8 mM MOPS, 0.2 mM EDTA, pH 7.0), into which were added 5-10 ngof active enzyme with 200 μM substrate (Kemptide). The reactions wereinitiated by addition of Mg/ATP mix (10 mM MgAcetate+15 μM ATP with30-50 kBq per well of [γ-³³P]-ATP) and mixtures incubated for 40 min atroom temperature. Reactions were stopped by addition of 3% phosphoricacid, followed by filtration through p81 filterplates (WhatmanPolyfiltronics, Kent, UK). After washing 5 times with 75 mM aqorthophosphoric acid and once in methanol, plates were dried,scintillant added and incorporated radioactivity measured in ascintillation counter (TopCount, Packard Instruments, Pangbourne, Berks,UK). Compounds for kinase assay were made up as 10 mM stocks in DMSO anddiluted into 10% DMSO in assay buffer. Data was analysed usingcurve-fitting software (XLfit version 2.0.9, IDBS, Guildford, Surrey,UK) to determine IC₅₀ values (concentration of test compound whichinhibits kinase activity by 50%).

Results are summarized in Table 2 and a more extensive kinaseselectivity panel for selected compounds is shown in Table 3.

Example 4

MTT cytotoxicity assay. The compounds from Example 2 were subjected to astandard cellular proliferation assay using human tumour cell linesobtained from the ATCC (American Type Culture Collection, 10801University Boulevard, Manessas, Va. 20110-2209, USA). Standard 72-h MTT(thiazolyl blue; 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide) assays were performed (Haselsberger, K.; Peterson, D. C.;Thomas, D. G.; Darling, J. L. Anti Cancer Drugs 1996, 7, 331-8;Loveland, B. E.; Johns, T. G.; Mackay, I. R.; Vaillant, F.; Wang, Z. X.;Hertzog, P. J. Biochemistry International 1992, 27, 501-10). In short:cells were seeded into 96-well plates according to doubling time andincubated overnight at 37° C. Test compounds were made up in DMSO and a1/3 dilution series prepared in 100 μL cell media, added to cells (intriplicates) and incubated for 72 ho at 37° C. MTT was made up as astock of 5 mg/mL in cell media and filter-sterilised. Media was removedfrom cells followed by a wash with 200 μL PBS.

MTT solution was then added at 20 μL per well and incubated in the darkat 37° C. for 4 h. MTT solution was removed and cells again washed with200 μL PBS. MTT dye was solubilised with 200 μL per well of DMSO withagitation. Absorbance was read at 540 nm and data analysed usingcurve-fitting software (GraphPad Prism version 3.00 for Windows,GraphPad Software, San Diego Calif. USA) to determine IC₅₀ values(concentration of test compound which inhibits cell growth by 50%).Results are summarized in Table 4 and more extensive data for selectedcompounds is presented in Table 5.

Example 5

Anti-HIV Efficacy Evaluation in Fresh Human PBMCs

Representative compounds of the present invention were tested forantiviral activity against HIV-1 in human peripheral blood mononuclearcells (PBMCs) using the clinical paediatric HIV strain RoJo or WeJo.PBMCs were cultured under conditions which promote cell survival and HIVreplication. Antiviral activity was tested for from 6-9 log₁₀ serialdilutions of a 100 μM compound stock solution in DMSO. The followingparameters were derived: IC₅₀ and IC₉₀ (concentrations inhibiting virusreplication by 50 and 90%, respectively, TC₅₀ (concentration decreasingcell viability by 50%), and TI (therapeutic index: TC₅₀/IC₅₀).

Fresh PBMCs, seronegative for HIV and HBV, were isolated from screeneddonors (Interstate Blood Bank, Inc. Memphis, Term.). Cells werepelleted/washed 2-3 times by low speed centrifugation and re-suspensionin PBS to remove contaminating platelets. The Leukophoresed blood wasthen diluted with Dulbecco's Phosphate Buffered Saline (DPBS) andlayered over Lymphocyte Separation Medium (LSM; Cellgro® by Mediatech,Inc.; density 1.078±0.002 g/mL; Cat.# 85-072-CL) in a 50 mL centrifugetube and then centrifuged. Banded PBMCs were gently aspirated from theresulting interface and subsequently washed with PBS by low speedcentrifugation. After the final wash, cells were enumerated by trypanblue exclusion and re-suspended in RPMI 1640 supplemented with fetalbovine serum (FBS), and L-glutamine, Phytohemagglutinin (PHA-P, Sigma).The cells were allowed to incubate at 37° C. After incubation, PBMCswere centrifuged and resuspended in RPMI 1640 with FBS, L-glutamine,penicillin, streptomycin, gentamycin, and recombinant human IL-2 (R&DSystems, Inc). IL-2 is included in the culture medium to maintain thecell division initiated by the PHA mitogenic stimulation. PBMCs weremaintained in this with bi-weekly medium changes until used in the assayprotocol. Cells were kept in culture for a maximum of two weeks beforebeing deemed too old for use in assays and discarded. Monocytes weredepleted from the culture as the result of adherence to the tissueculture flask.

For the standard PBMC assay, PHA-P stimulated cells from at least twonormal donors were pooled, diluted and plated in the interior wells of a96-well round bottom microplate. Pooling of mononuclear cells from morethan one donor was used to minimise the variability observed betweenindividual donors, which results from quantitative and qualitativedifferences in HIV infection and overall response to the PHA and IL-2 ofprimary lymphocyte populations. Each plate contained virus/cell controlwells (cells plus virus), experimental wells (drug plus cells plusvirus) and compound control wells (drug plus media without cells,necessary for MTS monitoring of cytotoxicity). Since HIV-1 is notcytopathic to PBMCs, this allows the use of the same assay plate forboth antiviral activity and cytotoxicity measurements. Test drugdilutions were prepared in microtiter tubes and each concentration wasplaced in appropriate wells using the standard format. A predetermineddilution of virus stock was placed in each test well (final MOI≅0.1).The PBMC cultures were maintained for seven days following infection at37° C., 5% CO₂. After this period, cell-free supernatant samples werecollected for analysis of reverse transcriptase activity and/or HIV p24content. Following removal of supernatant samples, compound cytotoxicitywas measured by addition of MTS to the plates for determination of cellviability. Wells were also examined microscopically and anyabnormalities were noted.

Reverse transcriptase activity assay: A microtiter plate-based reversetranscriptase (RT) reaction was utilised (Buckheit et al., AIDS Researchand Human Retroviruses 7:295-302, 1991). Tritiated thymidinetriphosphate (³H-TTP, 80 Ci/mmol, NEN) was received in 1:1 dH₂O:Ethanolat 1 mCi/mL. Poly rA:oligo dT template:primer (Pharmacia) was preparedas a stock solution, followed by aliquoting and storage at −20° C. TheRT reaction buffer was prepared fresh on a daily basis. The finalreaction mixture was prepared by combining ³H-TTP, dH₂O, poly rA:oligodT stock and reaction buffer. This reaction mixture was placed in around bottom microtiter plate and supernatant containing virus was addedand mixed. The plate was incubated at 37° C. for 60 minutes. Followingincubation, the reaction volume was spotted onto DE81 filter-mats(Wallac), in a sodium phosphate buffer or 2×SSC (Life Technologies).Next they were washed in distilled water, in 70% ethanol, and thendried. Incorporated radioactivity (counts per minute, CPM) wasquantified using standard liquid scintillation techniques. The resultsfor selected compounds of the invention are shown below in Table 6.

Various modifications and variations of the described aspects of theinvention will be apparent to those skilled in the art without departingfrom the scope and spirit of the invention. Although the invention hasbeen described in connection with specific preferred embodiments, itshould be understood that the invention as claimed should not be undulylimited to such specific embodiments. Indeed, various modifications ofthe described modes of carrying out the invention which are obvious tothose skilled in the relevant fields are intended to be within the scopeof the following claims. TABLE 1 Example compounds No. Structure Name 1

[4-(2-Amino-4-methyl-thiazol-5-yl)- pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine 2

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine 3

[4-(2-N-Methylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholinophenyl)-amine 4

[4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine 5

1-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1- yl)-ethanone 6

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-piperazin-1-yl-phenyl)-amine 7

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4′-2″ethoxylethanolpiperazino)- phenyl]-amine 8

3-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1 -yl)-propan-1-ol 9

2-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin- 1-yl)-ethanol 10

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4-methanesulfonyl-piperazin- 1-yl)-phenyl]-amine 11

[4-(4-Benzyl-piperazin-1-yl)-phenyl]-[4-(4-methyl-2-methylamino-thiazol-5-yl)- pyrimidin-2-yl]-amine 12

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4-methyl-piperazin-1-yl)- phenyl]-amine 13

3-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}- propionamide 14

(2S)-2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]- thiazol-2-yl}-propionamide 15

(2R,3R)-2-Amino-3-hydroxy-N-{4- methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide 16

(2R)-2-Amino-N- {4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2- yl}-butyramide 17

(2S,3S)-2-Amino-3-hydroxy-N-{4- methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide 18

4-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2- yl}-butyramide 19

3-Amino-N-{4-methyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]- thiazol-2-yl}-propionamide 20

3-Bromo-N-{5-[2-(4-fluoro- phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamide 21

N-{5-[2-(4-Fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3- morpholin-4-yl-propionamide 22

N-{4-Methyl-5-[2-(3-nitro-phenylamino)- pyrimidin-4-yl]-thiazol-2-yl}-3-morpholin-4-yl-propionamide 23

N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-3-(4-methyl- piperazin-1-yl)-propionamide24

2-Chloro-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2- yl}-acetamide 25

2-Chloro-N-{5-[2-(3-chloro- phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide 26

2-Chloro-N-{5-[2-(3-methoxy- phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}acetamide 27

2-Chloro-N-{5-[2-(4-dimethylamino-phenylamino)-pyrimidin-4-yl]-4-methyl- thiazol-2-yl}-acetamide 28

4-({4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-ylcarbamoyl}- methyl)-piperazine-1-carboxylicacid tert- butyl ester 29

N-{5-[2-(4-Dimethylamino-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-2-[2-(2-hydroxy-ethoxy)-ethylamino]- acetamide 30

6-[5-(2-Oxo-hexahydro-thieno[3,4- d]imidazol-4-yl)-pentanoylamino]-hexanoic acid (2-{4-methyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-thiazol-2-ylcarbamoyl}-ethyl)-amide 31

N-{5-[2-(4-Fluoro-phenylamino)- pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-methanesulfonamide 32

N- {4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-methane sulfonamide 33

2-Chloro-N-{5-[2-(4-fluoro- phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide 34

2-Chloro-N-{5-[2-(4-chloro- phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide 35

N-{5-[2-(4-Chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3- morpholin-4-yl-propionamide 36

N-{5-[2-(4-Chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3- (2-diethylamino-ethylamino)-propionamide 37

N-{5-[2-(4-Chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3- (2-morpholin-4-yl-ethylamino)-propionamide 38

N-{5-[2-(4-Methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3- morpholin-4-yl-propionamide 39

N-{5-[2-(3-Methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3- morpholin-4-yl-propionamide 40

N-{5-[2-(4-Methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-(4-methyl-piperazin-1-yl)-propionamide 45

N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-acetamide 48

N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-N-methyl- acetamide 49

1-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin- 1-yl)-propan-2-ol 50

2-Chloro-N-{4-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}- acetamide 51

N-(4-[4-(2,4-Dimethyl-thiazol-5-yl)- pyrimidin-2-ylamino]-phenyl}-2-morpholin-4-yl-acetamide 52

N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)- pyrimidin-2-ylamino]-phenyl}-2-[1,2,4]triazol-1-yl-acetamide 53

N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)- pyrimidin-2-ylamino]-phenyl}-2-pyrrolidin-1-yl-acetamide 54

N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)- pyrimidin-2-ylamino]-phenyl}-2-imidazol-1-yl-acetamide 55

3-[4-(4-Methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenol 56

[4-(4-Methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl- phenyl)-amine 57

N,N-Dimethyl-N′-[4-(4-methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2- yl]-benzene-1,4-diamine 59

2-{4-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}- ethanol 61

1-(4-{4-[4-(4-Methyl-2-methylamino- thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-ethanone 62

[4-(4-Methyl-2-methylamino-thiazol-5 yl)-pyrimidin-2-yl]-(4-piperazin-l-yl- phenyl)-amine 63

N-{3-[4-(4-Methyl-2-methylamino- thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-acetamide 64

N-{3-[4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}- acetamide 65

(3-Aminomethyl-phenyl)-[4-(2- ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-amine 66

N-{3-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-acetamide 67

(3-Aminomethyl-phenyl)-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2- yl]-amine 68

{3-[4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}- methanol 71

[4-(4-Methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-yl]-(3-nitro-phenyl)-amine 72

{2-Chloro-5-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}- methanol 73

{2-Chloro-5-[4-(4-methyl-2-methylamino-thiazo1-5-yl)-pyrimidin-2-ylamino]- phenyl}-methanol 76

[4-(2-Amino-4-methyl-thiazol-5-yl)- pyrimidin-2-yl]-(4-methanesulfonyl-phenyl)-amine 77

[4-(2-Methoxy-ethoxy)-3-nitro-phenyl]-[4-(4-methyl-2-methylamino-thiazol-5-yl)- pyrimidin-2-yl]-amine 81

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[3-(2-morpholin-4-yl-ethoxymethyl)- phenyl]-amine 82

C,C,C-Trifluoro-N-{3-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-methanesulfonamide 83

N-{3-[4-(4-Methyl-2-methylamino- thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-methanesulfonamide 84

[4-(2-Amino-4-methyl-thiazol-5-yl)- pyrimidin-2-yl]-(3-methanesulfonyl-phenyl)-amine 85

[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-methanesulfonyl-phenyl)-amine 91

{3-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}- methanol 92

3,4-Dimethyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-3H-thiazol- 2-one 93

3,4-Dimethyl-5-{2-[4-(4-methyl- piperazin-1-yl)-phenylamino]-pyrimidin-4-yl}-3H-thiazol-2-one

TABLE 2 Inhibition of protein kinases by example compounds (refer Table1). Kinase Inhibition IC₅₀ (μM) CDK1 CDK2 CDK2 CDK4 CDK7 CDK9 cyclincyclin cyclin cyclin cyclin cyclin GSK- No. B¹ A¹ E¹ D1¹ H¹ T1¹ 3β¹PLK-1¹ ARK-2² 1 17 0.70 0.81 2.4 30 2.7 >100 98 0.011 2 75 2.2 3.9 3.997 23 >100 >100 3 71 4.7 0.43 1.4 106 12 >100 >150 4 30 1.1 0.90 0.43 121.8 >100 >100 5 5.6 1.1 0.87 1.7 5.6 6.1 21 35 6 3.0 0.85 0.71 0.39 1.31.0 5.2 13 7 4.2 1.3 1.8 0.62 2.2 8 4.9 1.1 1.2 0.36 0.97 0.51 39 >150 95.2 1.2 2.2 0.43 1.3 0.21 10 51 4.4 15 11 11 2.4 2.2 0.26 0.0098 0.0191.1 6.0 19 12 4.2 1.0 1.8 0.19 1.1 0.28 53 55 13 5.6 0.57 0.28 0.67 0.370.042 14 0.068 2.2 0.34 15 5.4 0.85 0.13 2.0 0.34 0.070 0.61 >150 16 2.80.65 0.32 6.7 1.1 0.11 0.68 >150 2.8 17 2.0 0.21 18 0.18 1.1 0.53 20 1.90.52 0.076 0.77 0.037 21 0.54 0.32 0.097 1.3 4.9 0.46 14 >200 22 0.240.098 0.0025 1.7 0.20 0.11 0.25 >100 23 3.1 1.4 0.19 3.0 0.81 0.40 1.224 24 1.1 0.44 0.0058 25 9.4 3.0 0.22 0.97 3.2 0.68 0.083 28 36 12 2.629 29 0.86 0.49 0.47 1.1 1.2 0.56 31 0.30 5.6 32 0.005 1.1 0.0014 0.2133 0.23 0.68 34 1.4 7.0 0.73 35 15 3.0 0.80 4.7 1.8 36 33 13 3.4 8.8 4.04.8 37 >100 16 8.0 18 6.3 38 1.9 0.58 2.7 1.8 1.1 39 11 2.7 1.2 32 15 4061 14 64 7.4 8.9 45 2.5 0.84 0.66 0.37 17 0.24 48 12 1.7 2.1 2.6 3.5 503.4 0.89 0.39 0.95 13 0.0018 51 11 2.9 1.7 0.40 9.6 52 2.5 1.3 0.44 0.182.0 53 5.2 5.3 0.52 0.040 0.44 0.093 23 54 1.3 57 0.098 0.032 2.1 0.1119 55 2.4 61 0.079 1.0 2.2 2.1 67 56 18 68 0.60 0.022 0.85 17 >100 577.7 73 0.35 0.071 0.19 12 74 59 0.71 0.11 0.14 0.086 2.6 0.47 2.2 61 2.52.8 0.60 0.042 2.3 1.5 6.8 62 0.98 1.5 0.21 0.0070 0.041 0.098 4.7 63 4812 1.7 7.7 20 2.7 8.8 46 64 0.74 0.31 0.080 0.13 0.59 0.10 2.1 18 650.33 0.11 >100 66 0.12 0.10 0.11 0.63 2.1 67 0.42 0.24 >100 68 0.150.061 0.065 0.042 0.48 0.82 71 0.33 0.0060 0.22 2.4 4.2 2.4 72 62 120.73 25 9.6 4.1 48 73 1.7 1.3 1.0 0.23 2.0 0.55 5.2 76 1.8 0.14 0.15 3.211 5.4 77 72 1.0 0.15 3.4 1.0 0.26 6.1 82 2.7 1.3 0.014 2.3 4.0 1.2 830.48 0.15 0.025 0.67 0.37 1.0 84 0.14 0.05 0.076 0.3 0.43 0.30 85 0.0480.001 0.028 3.8 11 91 0.12 0.10 0.11 0.63 92 15 1.2 0.64 1.3 2.8 0.47 934.4 1.1 0.84 0.51 0.36 0.3 0.43¹Refer to Table 3 for explanation of abbreviations;²ARK-2: aurora kinase-2 (also known as aurora A kinase).

TABLE 3 Kinase specificity of selected compounds (IC₅₀, μM) CompoundKinase 1 3 11 15 16 CDK2/E¹ 0.48 0.68 0.26 0.15 0.35 CDK2/A² 0.44 0.442.2 0.40 0.65 CDK1/B1³ 21 >100 2.4 1.6 2.8 CDK4/D1⁴ 2.2 0.15 0.0098 1.66.7 CDK7/H⁵ 56 >100 0.019 0.39 0.97 CDK9/T1⁶ 2.3 8.5 1.1 0.11 0.20ERK2⁷ >100 >100 >100 >100 >100 p70/S6⁸ 2.3 2.6 >100 >100 8.0CK2⁹ >100 >100 >100 >100 >100 PKCα¹⁰ >100 >100 >100 >100 53Akt/PKB¹¹ >100 >100 >100 >100 >100 PKA¹² 5.8 39 11 2.0 4.9SAPK2a¹³ >100 >100 >100 >100 >100 PLK1¹⁴ >100 >100 19 >100 >100 CaMKII¹⁵26 >100 56 3.9 11 Abl¹⁶ >100 50 72 0.76 1.5 GSK-3¹⁷ >100 >100 6.0 0.540.68¹CDK2/cyclin E complex;²CDK2/cyclin A complex;³CDK 1/cyclin B1 complex;⁴CDK4/cyclin D1 complex;⁵CDK7/cyclin H/MAT 1 complex;⁶CDK9/cyclin T1 complex;⁷extracellular-signal-regulated kinase 2;⁸p70 ribosomal protein S6 kinase;⁹casein kinase 2;¹⁰protein kinase C α;¹¹protein kinase B;¹²cAMP-dependent protein kinase;¹³stress-activated protein kinase 2a;¹⁴polo-like kinase 1;¹⁵calmodulin-depependent kinase II;¹⁶Ableson tyrosine kinase;¹⁷glycogen synthase kinase 3β.

TABLE 4 Anti-proliferative activity against human cancer cell lines(refer Table 1) 72-h MTT IC₅₀ (μM) No. A549 HT29 Saos-2 1 2.1 1.7 1.9 23.5 3.3 4.8 3 3.7 2.8 3.1 4 0.77 0.92 1.2 5 3.8 2.2 3.9 6 1.3 1.1 0.78 73.9 1.6 1.6 8 0.61 0.80 0.38 9 3.0 2.0 2.0 10 11 6.4 11 2.2 1.6 3.6 120.71 0.74 0.43 13 3.1 2.8 1.9 14 0.99 0.73 1.5 15 1.1 1.0 1.9 16 0.530.29 17 1.1 1.2 1.2 18 2.5 2.4 1.1 20 5.8 6.3 21 8.6 4.1 4.3 22 0.810.52 0.60 23 3.8 1.1 4.4 24 0.14 0.14 0.17 25 0.97 1.3 1.6 28 9.9 6.7415 29 0.69 2.6 0.72 31 2.0 4.1 0.81 32 0.10 0.17 0.16 33 0.33 0.11 0.3034 3.9 3.2 3.3 35 15 7.7 26 36 26 9.6 38 37 35 15 73 38 2.7 1.7 5.3 390.80 0.72 0.95 40 4.4 0.73 4.3 45 2.6 2.2 2.8 47 2.7 0.35 1.6 48 3.0 2.63.8 50 0.16 0.16 0.16 51 1.9 1.4 1.1 52 1.6 1.6 1.1 53 0.77 0.95 0.53 542.9 2.7 1.9 55 2.3 5.1 1.4 56 4.4 2.9 5.0 57 2.7 0.24 3.8 59 2.4 1.7 1.961 0.72 0.53 1.0 62 0.19 0.18 0.26 63 0.98 1.4 1.2 64 0.19 0.41 0.34 653.2 4.8 0.65 67 14 14 1.1 71 80 71 10 72 32 20 18 73 1.5 5.5 2.9 76 5.81.8 1.3 77 0.31 0.21 0.35

TABLE 5 In vitro antiproliferative activity of selected compounds (72-hMTT, IC₅₀, μM) Cell line Desig- Compound Type nation 1 11 15 16 Boneosteosarcoma Saos-2 0.1 3.7 0.4 0.6 Bone osteosarcoma U2OS 2.1 2.3 1.020.48 Breast MCF-7 >5 1.9 0.9 0.39 Cervix Hela 1.8 6.2 0.7 0.4 Colon HT291.1 1.6 0.5 0.3 Colon Lovo 0.9 2.0 0.7 0.3 Colon H1299 0.9 1.1 1.3 0.6Colon HCT-116 0.9 0.6 0.6 0.3 Gastric adenocarcinoma AGS 1.1 1.3 1.1 0.3Leiomyosarcoma SKUT-1B 0.3 0.2 0.1 Leiomyosarcoma SKUT-1 0.9 0.8 0.9 0.2Chronic myelogenous K562 3.8 2.1 4.6 2.5 leukaemia Leukemia CCRF-CEM 0.90.5 2.6 1.1 Promyelocytic leukaemia HL60 1.8 1.7 2.2 0.6 Lung nci-H4600.2 0.7 1.2 0.3 Lung A549 1.0 2.2 0.6 0.5 Neuroblastoma SK-N-MC 0.3 0.60.5 0.4 Osteogenic sarcoma SJSA-1 >5 4.3 1.9 1.0 Prostate DU-145 1.5 1.01.3 0.6 Skin keratinocytes Hacat 1.1 1.0 1.5 1.1 Uterine Messa 0.2 0.10.9 0.4 Uterine Messa-Dx5 0.2 0.2 0.4 0.1 Average (all transformed 1.11.6 1.2 0.6 cells) SD (all transformed cells) 0.9 1.4 1.0 0.5 Median(all transformed 1.0 1.1 0.9 0.4 cells) Foreskin fibroblast (non-Hs27 >5 19 1.7 >5 transformed) Foetal lung fibroblast IMR-90 >5 31 2.51.7 (non-transformed) Foetal lung fibroblast WI38 >5 22 >5 1.4(non-transformed)

TABLE 6 Summary of anti-HIV activity HIV-1/PBMC IC₅₀ Compound (nM) IC₉₀(nM) PBMC TC₅₀ (μM) TI AZT^(a) 4 10 >1 >231 1 1,327 2,645 6.1 4.6 3 297679 >100 >337 4 166 295 9.4 57 15 124 385 2.4 20 53 812 871 1.6 1.9^(a)AZT: Azidothymidine; anti-HIV drug in clinical use as positivecontrol.

1. A compound of formula I, or a pharmaceutically acceptable saltthereof,

wherein: (A) one of X¹ and X² is S, and the other of X¹ and X² is N; “a”is a single bond; and “b”, “c”, “d”, “e” and “f” are single or doublebonds so as to form a thiazolyl ring; R² is independently as definedbelow for R¹, R³⁻⁸; or (B) one of X¹ and X² is S, and the other of X¹and X² is NR¹⁷; “a” and “d” are each double bonds; and “b”, “c”, “e” and“f” are each single bonds; R² is oxo; R¹⁷ is H or alkyl; where: Z is NH,NHCO, NHSO₂, NHCH₂, CH₂, CH₂CH₂, CH═CH, SO₂, or SO; R¹, R³, R⁴, R⁵, R⁶,R⁷ and R⁸ are each independently H, alkyl, alkyl-R⁹, aryl, aryl-R⁹,aralkyl, aralkyl-R⁹, halogeno, NO₂, CN, OH, O-alkyl, COR⁹, COOR⁹,O-aryl, O—R⁹, NH₂, NH-alkyl, NH-aryl, N-(alkyl)₂, N-(aryl)₂,N-(alkyl)(aryl), NH—R⁹, N—(R⁹)(R¹⁰), N-(alkyl)(R⁹), N-(aryl)(R⁹), COOH,CONH₂, CONH-alkyl, CONH-aryl, CON-(alkyl)(R⁹), CON(aryl)(R⁹), CONH—R⁹,CON-(R⁹)(R¹⁰), SO₃H, SO₂-alkyl, SO₂-alkyl-R⁹, SO₂-aryl, SO₂-aryl-R⁹,SO₂NH₂, SO₂NH—R⁹, SO₂N—(R⁹)(R¹⁰), CF₃, CO-alkyl, CO-alkyl-R⁹, CO-aryl,CO-aryl-R⁹ or R¹¹, wherein alkyl, aryl, aralkyl groups may be furthersubstituted with one or more groups selected from haoloeno, NO₂, OH,O-methyl, NH₂, COOH, CONH₂ and CF₃; wherein at least one of R¹, R², R³,R⁴, R⁵, R⁶, R⁷ and R⁸ is an R⁹ or R¹⁰-containing group, or is R¹¹; R⁹and R¹⁰ are each independently solubilising groups selected from: (i) amono-, di- or polyhydroxylated alicyclic group; a di- orpolyhydroxylated aliphatic or aromatic group; a carbohydrate derivative;an O- and/or S-containing heterocyclic group optionally substituted byone or more hydroxyl groups; an aliphatic or aromatic group containing acarboxamide, sulfoxide, sulfone, or sulfonamide function; or ahalogenated alkylcarbonyl group; (ii) COOH, SO₃H, OSO₃H, PO₃H₂, orOPO₃H₂; (iii) Y, where Y is selected from an alicyclic, aromatic, orheterocyclic group comprising one or more of the functions ═N—, —O—,—NH₂, —NH—, a quarternary amine salt, guanidine, and amidine, where Y isoptionally substituted by one or more substituents selected from:SO₂-alkyl; alkyl optionally substituted by one or more OH groups;CO-alkyl; aralkyl; COO-alkyl; and an ether group optionally substitutedby one or more OH groups; and where Y is other than pyridinyl; (iv) anatural or unnatural amino acid, a peptide or a peptide derivative; eachR¹¹ is a solubilising group as defined for R⁹ and R¹⁰ in (i) or (iv)above; or is selected from: (v) OSO₃H, PO₃H₂, or OPO₃H₂; (vi) Y asdefined above, but exluding guanidine and quarternary amine salts; (vii)NHCO(CH₂)_(m)[NHCO(CH₂)_(m′)]_(p)[NHCO(CH₂)_(m″)]_(q)Y orNHCO(CH₂)_(t)NH(CH₂)_(t′)Y where p and q are each 0 or 1, and m, m′, m″,t and t′ are each independently an integer from 1 to 10; and (viii)(CH₂)_(n)NR¹⁴COR¹², (CH₂)_(n′)NR¹⁵SO₂R¹³, or SO₂R⁶, where R², R¹³ andR¹⁶ are each alkyl groups optionally comprising one or more heteroatoms,and which are optionally substituted by one or more substituentsselected from OH, NH₂, halogen and NO₂, R¹⁴ and R¹⁵ are eachindependently H or alkyl, and n and n′ are each independently 0, 1, 2,or 3; (ix) an ether or polyether optionally substituted by one or morehydroxyl groups or one or more Y groups; (x) (CH₂)_(r)NH₂; where r is 0,1, 2, or 3; (xi) (CH₂)_(r′)OH; where r′ is 0, 1, 2, or 3; with theproviso that the compound is other than:2-Chloro-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-acetamide;N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-methanesulfonamide;2-Chloro-N-{5-[2-(4-fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide;{3-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-methanol;2-{4-[4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-ethanol;or2-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-ethanol.2. A compound according to claim 1 of formula Ib, or a pharmaceuticallyacceptable salt thereof,

wherein one of X¹ and X² is S, and the other of X¹ and X² is N, and Z,R¹⁻⁸ are as defined in claim
 1. 3. A compound according to claim 2,wherein X¹ is S and X² is N.
 4. A compound according to claim 1, whereinZ is NH.
 5. A compound according to claim 1, wherein R³ is H.
 6. Acompound according to claim 1, wherein at least one of R², R⁵, R⁶ or R⁷is an R⁹ or R¹⁰-containing group, or is R¹¹.
 7. A compound according toclaim 1, wherein X¹ is S, X² is N, Z is NH, R¹ is Me, R² is alkyl oramino, R³ is H, one or two of R⁵, R⁶, and R⁷ are CF₃, OH, O-alkyl,halogeno, NO₂, NH₂, NH-alkyl or N-(alkyl)₂ and at least one of R², R⁵,R⁶ or R⁷ is an R⁹ or R¹⁰-containing group, or is R¹¹.
 8. A compoundaccording to claim 1, wherein at least one of R¹, R², R³, R⁴, R⁵, R⁶, R⁷and R⁸ is R¹¹.
 9. A compound according to claim 1, wherein thesolubilising group is R¹¹, and R¹¹ is: (b) Y as defined in claim 1, butexluding guanidine, where Y can also be an alicyclic, aromatic, orheterocyclic group comprising one or more ═N— groups; (b)NHCO(CH₂)_(m)[NHCO(CH₂)_(m′)]_(p)[NHCO(CH₂)_(m″)]_(q)Y orNHCO(CH₂)_(t)NH(CH₂)_(t′)Y where p and q are each 0 or 1, and m, m′, m″,t and t′ are each an integer from 1 to 10; or (c) (CH₂)_(n)NR¹⁴COR¹²,(CH₂)_(n′)NR¹⁵SO₂R¹³, or SO₂R¹⁶, where R¹², R¹³ and R¹⁶ are each alkylgroups optionally comprising one or more heteroatoms, and which aresubstituted by one or more substituents selected from OH, NH₂, halogenand NO₂, R¹⁴ and R¹⁵ are each independently H or alkyl, and n and n′ areeach independently 0, 1, 2, or
 3. 10. A compound according to claim 9,where Y is an alicyclic group comprising one or more of the functions—O—, NH₂, —NH—, ═N—, a quarternary amine salt, or amidine, and wherein Yis optionally substituted by one or more substituents as defined inclaim
 1. 11. A compound according to claim 1, wherein Y is a morpholineor piperazine group, each of which may be optionally substituted by oneor more substituents selected from SO₂-alkyl, alkyl optionallysubstituted by one or more OH groups, CO-alkyl, aralkyl, COO-alkyl, andan ether group optionally substituted by one or more OH groups
 12. Acompound according to claim 1, wherein Y is a2-oxo-hexahydro-thien[3,4-d]imidazole group.
 13. A compound according toclaim 1, wherein at least one of R², R⁶ or R⁷ is R¹¹.
 14. A compoundaccording to claim 1, wherein R¹¹ is selected from the following:


15. A compound according to claim 13 or claim 14, wherein R⁶ or R⁷ isR¹¹.
 16. A compound according to claim 15, wherein R⁶ is R¹¹ and R², R⁴,R⁵, R⁷ and R⁸ are each independently selected from alkyl, H, CF₃, OH,O-alkyl, halogeno, NO₂, NH₂, NH-alkyl and N-(alkyl)₂.
 17. A compoundaccording to claim 15, wherein R⁶ is R¹¹ and R², R⁴, R⁵, R⁷ and R⁸ areeach independently selected from alkyl, H, O-alkyl, halogeno, NO₂, NH₂and NH-alkyl.
 18. A compound according to claim 15, wherein R⁶ is R¹¹and R⁴, R⁵, R⁷ and R⁸ are all H and R² is selected from alkyl, O-alkyl,NH₂ and NH-alkyl.
 19. A compound according to claim 15, wherein R¹¹ isselected from:


20. A compound according to claim 15, wherein R⁷ is R¹¹ and R⁴, R⁵, R⁶,R⁸ are all H, and R² is selected from alkyl, O-alkyl, NH₂ and NH-alkyl.21. A compound according to claim 20, wherien R¹¹ is selected from:


22. A compound according to claim 13 or claim 14, wherein R² is R¹¹. 23.A compound according to claim 22, wherein R² is R¹¹ and R⁴, R⁵, R⁶, R⁷and R⁸ are each independently selected from alkyl, H. CF₃, OH, O-alkyl,halogeno, Na₂, NH₂, NH-alkyl and N-(alkyl)₂.
 24. A compound according toclaim 22, wherein R² is R¹ and R⁴, R⁵, R⁶, R⁷ and R³ are eachindependently selected from H. O-alkyl, halogeno, N-(alkyl)₂, NO₂.
 25. Acompound according to claim 22, wherein R² is R¹¹, one of R⁵ or R⁷ isselected from NO₂, alkoxy, halogeno and N-(alkyl)₂, and the remainder ofR⁴, R⁵, R⁶, R⁷ and R⁸ are all H.
 26. A compound according to claim 22,wherein R¹ is selected from:


27. A compound according to claim 1, wherein R¹ is methyl, Z is NH andR³ is H.
 28. A compound according to claim 1 of formula Id, or apharmaceutically acceptable salt thereof,


29. A compound according to claim 28 wherein R¹ and R³⁻⁸ are as definedin claim
 9. 30. A compound selected from the following: 1[4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine 2[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine 3[4-(2-N-Methylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholinophenyl)-amine 4[4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine 51-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-ethanone 6[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-piperazin-1-yl-phenyl)-amine 7[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4′-2″-ethoxylethanolpiperazino)-phenyl]-amine 83-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-propan-1-ol 92-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-ethanol 10[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4-methanesulfonyl-piperazin-1-yl)-phenyl]-amine 11[4-(4-Benzyl-piperazin-1-yl)-phenyl]-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-amine 12[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[4-(4-methyl-piperazin-1-yl)-phenyl]-amine 133-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide 14(2S)-2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide 15(2R,3R)-2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide 16(2R)-2-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide 17(2S,3S)-2-Amino-3-hydroxy-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide 184-Amino-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-butyramide 193-Amino-N-{4-methyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-propionamide 203-Bromo-N-{5-[2-(4-fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-propionamide 21N-{5-[2-(4-Fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-morpholin-4-yl-propionamide 22N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-3-morpholin-4-yl-propionamide 23N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-3-(4-methyl-piperazin-1-yl)-propionamide 242-Chloro-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-acetamide 252-Chloro-N-{5-[2-(3-chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide 262-Chloro-N-{5-[2-(3-methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide 272-Chloro-N-{5-[2-(4-dimethylamino-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide 284-({4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-ylcarbamoyl}-methyl)-piperazine-1-carboxylic acid tert-butylester 29 N-{5-[2-(4-Dimethylamino-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-2-[2-(2-hydroxy-ethoxy)-ethylamino]- acetamide 306-[5-(2-Oxo-hexahydro-thieno[3,4-d]imidazol-4-yl)-pentanoyl-amino]-hexanoic acid (2-{4-methyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-thiazol-2-ylcarbamoyl}-ethyl)- amide 31N-{5-[2-(4-Fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-methanesulfonamide 32N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-methane sulfonamide 332-Chloro-N-{5-[2-(4-fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide 342-Chloro-N-{5-[2-(4-chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide 35N-{5-[2-(4-Chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-morpholin-4-yl-propionamide 36N-{5-[2-(4-Chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-(2-diethylamino-ethylamino)-propionamide 37N-{5-[2-(4-Chloro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-(2-morpholin-4-yl-ethylamino)-propionamide 38N-{5-[2-(4-Methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-morpholin-4-yl-propionamide 39N-{5-[2-(3-Methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-morpholin-4-yl-propionamide 40N-{5-[2-(4-Methoxy-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-3-(4-methyl-piperazin-1-yl)-propionamide 45N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-acetamide 48N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-N-methyl-acetamide 491-(4-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-propan-2-ol 502-Chloro-N-{4-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-acetamide 51N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-2-morpholin-4-yl-acetamide 52N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-2-[1,2,4]triazol-1-yl-acetamide 53N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-2-pyrrolidin-1-yl-acetamide 54N-{4-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-2-imidazol-1-yl-acetamide 553-[4-(4-Methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenol 56[4-(4-Methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-yl]-(4-morpholin-4-yl-phenyl)-amine 57N,N-Dimethyl-N′-[4-(4-methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-yl]-benzene-1,4-diamine 592-{4-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-ethanol 611-(4-{4-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-piperazin-1-yl)-ethanone 62[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-(4-piperazin-1-yl-phenyl)-amine 63N-{3-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-acetamide 64N-{3-[4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-acetamide 65(3-Aminomethyl-phenyl)-[4-(2-ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-amine 66N-{3-[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-acetamide 67(3-Aminomethyl-phenyl)-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-amine 68{3-[4-(2-Ethylamino-4-methyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-methanol 71[4-(4-Methyl-2-morpholin-4-yl-thiazol-5-yl)-pyrimidin-2-yl]-(3-nitro-phenyl)-amine 72{2-Chloro-5-[4-(2,4-dimethyl-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-methanol 73{2-Chloro-5-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-methanol 76[4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-methanesulfonyl-phenyl)-amine 77[4-(2-Methoxy-ethoxy)-3-nitro-phenyl]-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-yl]-amine 81[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-[3-(2-morpholin-4-yl-ethoxymethyl)-phenyl]-amine 82C,C,C-Trifluoro-N-{3-[4-(4-methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-methanesulfonamide 83N-{3-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-benzyl}-methanesulfonamide 84[4-(2-Amino-4-methyl-thiazol-5-yl)-pyrimidin-2-yl]-(3-methanesulfonyl-phenyl)-amine 85[4-(2,4-Dimethyl-thiazol-5-yl)-pyrimidin-2-yl]-(4-methane-sulfonyl-phenyl)-amine 91{3-[4-(4-Methyl-2-methylamino-thiazol-5-yl)-pyrimidin-2-ylamino]-phenyl}-methanol 923,4-Dimethyl-5-[2-(4-morpholin-4-yl-phenylamino)-pyrimidin-4-yl]-3H-thiazol-2-one 933,4-Dimethyl-5-{2-[4-(4-methyl-piperazin-1-yl)-phenylamino]-pyrimidin-4-yl}-3H-thiazol-2-one


31. A compound according to claim 30, which is selected from thefollowing: [4], [8], [12], [14], [16], [22], [24], [25], [29], [32],[33], [39], [40], [50], [53], [61], [57], [62], [63], [64], [65] and[77].
 32. A compound according to claim 31, which is selected from thefollowing: [24], [25], [32], [33], [50], [62] and [64].
 33. A compoundaccording to claim 30, which is selected from the following: [11], [13],[14], [15], [20], [21], [22], [24], [25], [32], [50], [53], [54], [55],[56], [57], [59], [61], [62], [64], [68], [71], [82], 83], [84] and[85].
 34. A compound according to claim 33, which is selected from thefollowing: [11], [22], [24], [32], [50], [62], [71] and [85].
 35. Apharmaceutical composition comprising a compound according to any one ofclaims 1, 28, or 30, admixed with a pharmaceutically acceptable diluent,excipient or carrier.
 36. A method of treating a proliferative disorder,said method comprising administering to a mammal a therapeuticallyeffective amount of a compound according to any one of claims 1, 28, or30, such that the proliferative disorder is treated.
 37. The methodaccording to claim 36, wherein the proliferative disorder is cancer orleukaemia.
 38. The method according to claim 36, wherein said compoundis administered in combination with one or more other anticancercompounds.
 39. A method of treating a viral disorder, said methodcomprising administering to a mammal a therapeutically effective amountof a compound of formula Ia, or a pharmaceutically acceptable saltthereof,

wherein (A) one of X¹ and X² is S, and the other of X¹ and X² is N; “a”is a single bond; and “b”, “c”, “d”, “e” and “f” are single or doublebonds so as to form a thiazolyl ring; R² is independently as definedbelow for R¹, R³⁻⁸; or (B) one of X¹ and X² is S, and the other of X¹and X² is NR¹⁷; “a” and “d” are each double bonds; and “b”, “c”, “e” and“f” are each single bonds; R² is oxo; R¹⁷ is H or alkyl; where: Z is NH,NHCO, NHSO₂, NHCH₂, CH₂, CH₂CH₂, CH═CH, SO₂, or SO; R¹, R², R³, R⁴, R⁵,R⁶, R⁷ and R⁸ are each independently H, alkyl, alkyl-R⁹, aryl, aryl-R⁹,aralkyl, aralkyl-R⁹, halogeno, NO₂, CN, OH, O-alkyl, COR⁹, COOR⁹,O-aryl, O—R⁹, NH₂, NH-alkyl, NH-aryl, N-(alkyl)₂, N-(aryl)₂,N-(alkyl)(aryl), NH—R⁹, N—(R⁹)(R¹⁰), N-(alkyl)(R⁹), N-(aryl)(R⁹), COOH,CONH₂, CONH-alkyl, CONH-aryl, CON-(alkyl)(R⁹), CON(aryl)(R⁹), CONH—R⁹,CON—(R⁹)(R¹⁰), SO₃H, SO₂-alkyl, SO₂-alkyl-R⁹, SO₂-aryl, SO₂-aryl-R⁹,SO₂NH₂, SO₂NH—R⁹, SO₂N—(R⁹)(R¹⁰), CF₃, CO-alkyl, CO-alkyl-R⁹, CO-aryl,CO-aryl-R⁹ or R¹¹, wherein alkyl, aryl, aralkyl groups may be furthersubstituted with one or more groups selected from halogeno, NO₂, OH,O-methyl, NH₂, COOH, CONH₂ and CF₃; wherein at least one of R¹, R², R³,R⁴, R⁵, R⁶, R⁷ and R⁸ is an R⁹ or R¹⁰-containing group, or is R¹¹; R⁹and R¹⁰ are each independently solubilising groups selected from: (i) amono-, di- or polyhydroxylated alicyclic group; a di- orpolyhydroxylated aliphatic or aromatic group; a carbohydrate derivative;an O- and/or S-containing heterocyclic group optionally substituted byone or more hydroxyl groups; an aliphatic or aromatic group containing acarboxamide, sulfoxide, sulfone, or sulfonamide function; or ahalogenated alkylcarbonyl group; (ii) COOH, SO₃H, OSO₃H, PO₃H₂, orOPO₃H₂; (iii) Y, where Y is selected from an alicyclic, aromatic, orheterocyclic group comprising one or more of the functions ═N—, —O—,—NH₂, —NH—, a quarternary amine salt, guanidine, and amidine, where Y isoptionally substituted by one or more substituents selected from:SO₂-alkyl; alkyl optionally substituted by one or more OH groups;CO-alkyl; aralkyl; COO-alkyl; and an ether group optionally substitutedby one or more OH groups; and where Y is other than pyridinyl; (iv) anatural or unnatural amino acid, a peptide or a peptide derivative; eachR¹¹ is a solubilising group as defined for R⁹ and R¹⁰ in (i) or (iv)above; or is selected from: (v) OSO₃H, PO₃H₂, or OPO₃H₂; (vi) Y asdefined above, but exluding guanidine and quarternary amine salts; (vii)NHCO(CH₂)_(m)[NHCO(CH₂)_(m′)]_(p)[NHCO(CH₂)_(m″)]_(q)Y orNHCO(CH₂)_(t)NH(CH₂)_(t′)Y where p and q are each 0 or 1, and m, m′, m″,t and t′ are each an integer from 1 to 10; and (viii)(CH₂)_(n)NR¹⁴COR¹², (CH₂)_(n′)NR¹⁵SO₂R¹³, or SO₂R¹⁶, where R¹², R¹³ andR¹⁶ are each alkyl groups optionally comprising one or more heteroatoms,and which are substituted by one or more substituents selected from OH,NH₂, halogen and NO₂, R¹⁴ and R¹⁵ are each independently H or alkyl, andn and n′ are each independently 0, 1, 2, or 3; (ix) an ether orpolyether optionally substituted by one or more hydroxyl groups or oneor more Y groups; (x) (CH₂)_(r)NH₂; where r is 0, 1, 2, or 3; (xi)(CH₂)_(r′)OH; where r′ is 0, 1, 2, or 3, such that said viral disorderis treated.
 40. The method according to claim 39, wherein said compoundof formula Ia is as defined in claims 28 or
 30. 41. The method accordingto claim 39 wherein said compound of formula Ia is selected from thefollowing:N-{4-Methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}methanesulfonamide[32];2-Chloro-N-{4-methyl-5-[2-(3-nitro-phenylamino)-pyrimidin-4-yl]-thiazol-2-yl}-acetamide[24]; and2-Chloro-N-{5-[2-(4-fluoro-phenylamino)-pyrimidin-4-yl]-4-methyl-thiazol-2-yl}-acetamide[33].
 42. The method according to claim 39, wherein said compound offormula Ia is selected from the following: [1], [3], [4], [15] and [53].43. The method according to claim 39, wherein the viral disorder isselected from human cytomegalovirus (HCMV), herpes simplex virus type 1(HSV-1), human immunodeficiency virus type 1 (HIV-1), and varicellazoster virus (VZV).
 44. The method according to claims 36, wherein saidcompound inhibits a protein kinase.
 45. The method according to claim44, wherein said protein kinase is a cyclin dependent kinase.
 46. Themethod according to claim 45, wherein said protein dependent kinase isselected from CDK2, CDK7, CDK8 and CDK9.
 47. A method of identifyingfurther candidate compounds in an assay, comprising contacting acompound of 1, 28, or 30 with an enzyme selected from the groupconsisting of cyclin dependent kinases, GSK, and PLK enzymes in thepresence of a known substrate of said enzyme; and detecting any changein the interaction between said enzyme and said known substrate, suchthat a further candidate compound is identified.
 48. The methodaccording to claim 47, wherein said assay is a competitive bindingassay.
 49. The method according to claim 48, wherein said competitivebinding assay comprises contacting a compound of formula I with a cyclindependent kinase and a candidate compound and detecting any change inthe interaction between the compound of formula I and the cyclindependent kinase.
 50. The method according to claim 36, wherein theproliferative disorder is glomerulonephritis, rheumatoid arthritis,psoriasis or chronic obstructive pulmonary disorder.
 51. A method oftreating a CNS disorder, said method comprising administering to amammal a therapeutically effective amount of a compound according toformula I or Ia, or a pharmaceutically acceptable salt thereof, suchthat the CNS disorder is treated.
 52. The method according to claim 51,wherein the CNS disorder is Alzheimer's disease or bipolar disorder. 53.A method of treating alopecia, said method comprising administering to amammal a therapeutically effective amount of a compound according toformula I or Ia, or a pharmaceutically acceptable salt thereof, suchthat alopecia is treated.
 54. A method of treating a stroke, said methodcomprising administering to a mammal a therapeutically effective amountof a compound according to formula I or Ia, or a pharmaceuticallyacceptable salt thereof, such that said stroke is treated.
 55. Themethod according to claim 36, wherein the compound is administered in anamount sufficient to inhibit at least one PLK enzyme.
 56. The methodaccording to any one of claims 51-54, wherein the compound isadministered in an amount sufficient to inhibit at least one PLK enzyme.57. The method according to claim 55, wherein the PLK enzyme is PLK1.58. The method according to claim 56, wherein the PLK enzyme is PLK1.59. The method according to claim 36, wherein the compound isadministered in an amount sufficient to inhibit at least one CDK enzyme.60. The method according to any one of claims 51-54, wherein thecompound is administered in an amount sufficient to inhibit at least oneCDK enzyme.
 61. The method according to claim 59, wherein the CDK enzymeis CDK1, CDK2, CDK3, CDK4, CDK6, CDK7, CDK8 or CDK9.
 62. The methodaccording to claim 60, wherein the CDK enzyme is CDK1, CDK2, CDK3, CDK4,CDK6, CDK7, CDK8 or CDK9.
 63. The method according to claim 36, whereinthe compound is administered in an amount sufficient to inhibit aurorakinase.
 64. The method according to any one of claims 51-54, wherein thecompound is administered in an amount sufficient to inhibit aurorakinase.
 65. A method of treating diabetes, said method comprisingadministering to a mammal a therapeutically effective amount of acompound according to formula I or Ia, or a pharmaceutically acceptablesalt thereof, such that diabetes is treated.
 66. The method according toclaim 65, wherein the diabetes is Type II diabetes.
 67. The methodaccording to any one of claims 65 or 66, wherein the compound isadministered in an amount sufficient to inhibit GSK.
 68. The methodaccording to claim 67, wherein the compound is administered in an amountsufficient to inhibit GSK3β.